Article: 218945 of rec.radio.amateur.antenna From: "GS" References: <11mahd8l6rp635f@corp.supernews.com> <11mchqajdo0hj2d@corp.supernews.com> <11mclac3eu4m9ac@corp.supernews.com> Subject: Re: SWR meter for 2.4ghz Message-ID: Date: Tue, 1 Nov 2005 07:58:57 -0500 Check out http://www.eagle-1st.com/notes/rlbbas/bas.htm This should give you the info needed. Guenther Schweigl Degen Designs www.degendesigns.com info@degendesigns.com Article: 218946 of rec.radio.amateur.antenna From: "Jim Leder" References: <1130633563.967446.51040@g49g2000cwa.googlegroups.com> <313030303837383543660A4434@zetnet.co.uk> Subject: Re: Question on shooting a line Date: Tue, 1 Nov 2005 10:18:19 -0500 Message-ID: <3a319$43678733$42a1c3a6$4640@FUSE.NET> I've been using my old Bear hunting bow, and rubber tipped small game arrows with 20 lb fishing line for years. Works great, even though the neighbors think I'm crazy. After I get the line where I want it, I cut the line freeing the arrow and tie on a 1 oz. bullet sinker and pull the line up over the tree limbs that are 'extra' till the sinker is only over the target tree limb and then just drop the line and sinker. Works perfect. "Ed" wrote in message news:Xns9700AF3561EADspectrumhogstarbandn@207.106.93.175... > > >> Why not just use the rod and reel? Admittedly some can throw farther >> than they can cast. > > > I doubt there are very many people who can either throw, or cast a > line, at 70 feet, over a particular branch of a rather densely packed > conifer tree. I can do it, however, with a slingshot. A bow or crossbow > would be even better, I'll admit. > > > Ed > Article: 218947 of rec.radio.amateur.antenna From: Ron Subject: Re: Antenna gain question References: Message-ID: Date: Tue, 01 Nov 2005 16:09:22 GMT One more thing: Before thinking about all this, I always thought that since a high gain antenna has a narrower beam than a lower gain antenna, the high gain antenna "sees" a smaller part of the incoming field. I now believe this is wrong. The higher gain antenna sees a larger field area. But as the antenna is rotated the sum of all the rays decreases faster than if there were fewer of them. This is probably due to the rays from the outer edge of the field causing a faster decrease in the coherent summation of all rays than the closer in rays. Of course, as the rotation is continued, many (but not as many) of the rays add coherently again, giving rise to the side lobes. Ron, W4TQT Ron wrote: > This was only a mental exercise to help me visualize the concept of > gain. No resemblance to a real antenna or RF field was intended. > Thinking about it has helped me understand what antenna gain is > (assuming my conclusions are correct). And that's all it was supposed to > do. I hope it has helped someone else to do the same. > > Ron Article: 218948 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: Antenna gain question Date: Tue, 01 Nov 2005 10:09:54 -0800 Message-ID: References: Ron wrote: > This was only a mental exercise to help me visualize the concept of > gain. No resemblance to a real antenna or RF field was intended. > Thinking about it has helped me understand what antenna gain is > (assuming my conclusions are correct). And that's all it was supposed to > do. I hope it has helped someone else to do the same. > > Ron I think it was a good exercise, Ron - not unlike the kind seen in a good text book. My response at the bottom presumed some things about the nature of the sphere that were somewhat unclear in your message. I hope I presumed correctly. 73, ac6xg > Jim Kelley wrote: > >> >> >> Ron wrote: >> >>> Question (repeated here for convenience): >>> -------------------------------------------------------------------- >>> Assume a receiving antenna is in the center of a sphere and the >>> received signal is coming in equal amounts from all points on the >>> surface of the sphere. Which receiving antenna would capture more >>> power, an omni or a high gain beam? There are no noise and no losses. >>> --------------------------------------------------------------------- >>> >>> First, thanks for all the comments. They have helped me better >>> understand the answer. I am leaning toward the belief that the omni >>> (isotropic) antenna would capture more power and, as odd as it may >>> seem, would have more gain than a high gain beam (or any other >>> directional antenna for that matter). Here is my thinking: >>> >>> This is a very unusual RF field. Usually the field is assumed to be >>> planar with coherent rays - then antennas behave as expected. But >>> this field originates uniformly from all points on the surface of a >>> sphere. >> >> >> >> Uniformly inward, outward, or both? >> >>> It does not spread but converges at the focal point of the sphere. >> >> >> >> By focal point of the sphere do you mean the center of the sphere? >> How big of a sphere are we talking about, and where is the antenna in >> relation to the sphere? >> >>> An isotropic antenna placed at the focal point would collect all of >>> the rays whereas a directional antenna at would not. >> >> >> >> Probably. >> >>> Therefore, in this particular situation, the isotropic would have >>> higher gain and capture more power than any directional antenna. >> >> >> >> Not according to the accepted use of the term 'gain' in connection >> with antennas. >> >>> Please correct me if I am wrong. >>> >>> Ron, W4TQT >> >> >> >> In the instance you describe, the antenna with gain will pick up less >> signal than an antenna without gain. The gain antenna will be able to >> sense signal arriving from only a fraction of the sphere, whereas the >> isotropic antenna responds to signals arriving from the entire 4-pi >> sphere. Therefore, the antenna with less gain produces the greater >> signal level. But this should often be the case when a directional >> antenna is pointed away from most of the signal. The omni, on the >> other hand, is 'pointed toward' this particular signal in all directions. >> >> Out of curiosity, what kind of signal source are you interested in? >> >> ac6xg >> > Article: 218949 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: Antenna gain question Date: Tue, 01 Nov 2005 10:58:02 -0800 Message-ID: References: Ron wrote: > One more thing: Before thinking about all this, I always thought that > since a high gain antenna has a narrower beam than a lower gain antenna, > the high gain antenna "sees" a smaller part of the incoming field. I now > believe this is wrong. The higher gain antenna sees a larger field area. Hopefully no one else was led to that belief by the exercise. > But as the antenna is rotated the sum of all the rays decreases faster > than if there were fewer of them. This is probably due to the rays from > the outer edge of the field causing a faster decrease in the coherent > summation of all rays than the closer in rays. Of course, as the > rotation is continued, many (but not as many) of the rays add coherently > again, giving rise to the side lobes. Such a claim might be remotely plausible were it not for the fact that rotating a directional antenna does not "coherently sum all the rays". That's where the argument completely falls to the ground, as Monty Python might say. ac6xg > Ron, W4TQT > > Ron wrote: > >> This was only a mental exercise to help me visualize the concept of >> gain. No resemblance to a real antenna or RF field was intended. >> Thinking about it has helped me understand what antenna gain is >> (assuming my conclusions are correct). And that's all it was supposed >> to do. I hope it has helped someone else to do the same. >> >> Ron > > Article: 218950 of rec.radio.amateur.antenna From: "Dick, AA5VU" Subject: Source for Butternut Vertical parts Message-ID: Date: Tue, 01 Nov 2005 21:45:20 GMT A good friend in North Texas has some wind damage to his Butternut Vertical Antenna. Where can replacement parts be ordered? A web page URL would be great and I will relay the info to him aa5vu at arrl.net Article: 218951 of rec.radio.amateur.antenna From: "Caveat Lector" Subject: Need antenna article from Ham Radio Mag - Oct 1968 Message-ID: Date: Tue, 1 Nov 2005 14:02:31 -0800 Am posting this for a local ham - W6HPH, Fred Do not e-mail me or respond here please -- e-mail Fred direct at Brown Fred Fred asked: "Do you know anyone who has back issues of Ham Radio ? I promised FP5BU a copy of my antenna article which was in Ham Radio for October 1968 and reprinted in Ham Radio Horizons for May 1978 and I don't have a copy of either one. I just want to make a copy of my article to send to him." 73, Fred, W6HPH -- CL -- I doubt, therefore I might be ! Article: 218952 of rec.radio.amateur.antenna From: "Rod Maupin" Subject: Re: Source for Butternut Vertical parts Date: Tue, 1 Nov 2005 14:05:15 -0800 Message-ID: <11mfpkqa52c4i76@corp.supernews.com> References: Dick, Here is the link. I ordered a replacement cap. a couple of years ago for one of the resonators on my HF6V. It was around $38. Ouch! However, what choice do you have? http://www.bencher.com/ant_select.html Rod KI7CQ Article: 218953 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Antenna gain question References: Message-ID: Date: Tue, 01 Nov 2005 22:13:08 GMT Jim Kelley wrote: > Such a claim might be remotely plausible were it not for the fact that > rotating a directional antenna does not "coherently sum all the rays". Seems to me, a receiving Yagi causes constructive interference in the forward direction and destructive interference in the rearward direction. -- 73, Cecil http://www.qsl.net/w5dxp Article: 218954 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: Source for Butternut Vertical parts Date: Tue, 01 Nov 2005 13:56:58 -0800 Message-ID: References: http://www.bencher.com/ant_select.html Dick, AA5VU wrote: > A good friend in North Texas has some wind damage to his Butternut > Vertical Antenna. Where can replacement parts be ordered? A web page > URL would be great and I will relay the info to him > > aa5vu at arrl.net Article: 218955 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: Antenna gain question Date: Tue, 01 Nov 2005 14:35:08 -0800 Message-ID: References: Cecil Moore wrote: > Jim Kelley wrote: > >> Such a claim might be remotely plausible were it not for the fact that >> rotating a directional antenna does not "coherently sum all the rays". > > > Seems to me, a receiving Yagi causes constructive interference > in the forward direction and destructive interference in the > rearward direction. But does it seem the antenna causes destructive interference when the forward direction of the radiation is toward the rearward direction of the antenna, or does it seem like it causes constructive interference when the forward direction of the radiation is away from the rearward direction of the antenna....and if so, what does that have to do with "coherently summing all the rays by rotating the antenna"? Just wondering. ac6xg Article: 218956 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Copper tape antenna element-model Date: Tue, 01 Nov 2005 15:05:51 -0800 Message-ID: <11mft6g8kncqp1f@corp.supernews.com> References: <1130885403.965041.212270@g49g2000cwa.googlegroups.com> jgboyles@aol.com wrote: > Hi, I just aquired some 1/4" and 1/2" copper tape that is solderable. > Thinking about using as antenna elements in VHF yagi, UHF TV antenna as > well as other things. Question: When modelling, what wire diameter do > you use when the element is actually conductive tape? Thanks. > Gary N4AST The diameter of the model wire should be half the width of the tape. Roy Lewallen, W7EL Article: 218957 of rec.radio.amateur.antenna From: aRKay Subject: Re: Source for Butternut Vertical parts References: Message-ID: Date: Tue, 01 Nov 2005 23:41:59 GMT In article , "Dick, AA5VU" wrote: > A good friend in North Texas has some wind damage to his Butternut > Vertical Antenna. Where can replacement parts be ordered? A web page > URL would be great and I will relay the info to him > > aa5vu at arrl.net Thanks to all..... looks like Bencher is the place to go and I passed the links. End of topic 73, Dick AA5VU Article: 218958 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Antenna gain question References: Message-ID: Date: Wed, 02 Nov 2005 00:26:06 GMT Jim Kelley wrote: > ... what does that have to do with > "coherently summing all the rays by rotating the antenna"? Just wondering. "Coherently summing" certainly doesn't imply that interference is only constructive. An antenna is "coherently summing" all the rays it receives no matter what direction it is pointed. -- 73, Cecil http://www.qsl.net/w5dxp Article: 218959 of rec.radio.amateur.antenna From: w4sef@bellsouth.net (Steven Fritts) Subject: Re: Question on shooting a line Message-ID: <43680854.4156640@newsgroups.bellsouth.net> References: Date: Wed, 02 Nov 2005 00:29:34 GMT I use a 1.5 oz weight and 20# line. Works very well. Steve W4SEF On Sat, 29 Oct 2005 22:55:15 GMT, Ed wrote: > > I'm trying to shoot a line over a tree limb to hoist my next >generation of wire dipole. > > I'm using a slingshot, a 1 oz round lead fishing weight, and in this >case, 40# test fishing line. > > Although I have had fair success in the past, I'm having difficulties >lately. My weight won't pull the line down the other side of the limb >beyond where it stopped. > > My Question: What weight do you guys recommend? Does anyone know >what weight is used on the EZhang system? Comments sollicited. > > Right now I'm waiting for the wind to blow and hopefully move the tree >limb enough to make the hanging weight pull my live over to the point >where I can reach it. > > > Ed K7AAT Article: 218960 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: Antenna gain question Date: Tue, 01 Nov 2005 16:21:29 -0800 Message-ID: References: Cecil Moore wrote: > Jim Kelley wrote: > >> ... what does that have to do with "coherently summing all the rays by >> rotating the antenna"? Just wondering. > > "Coherently summing" certainly doesn't imply that interference > is only constructive. An antenna is "coherently summing" all > the rays it receives no matter what direction it is pointed. And still, rotating the antenna has nothing to do with summing the signals - coherently, or otherwise. Agreed? ac6xg Article: 218961 of rec.radio.amateur.antenna From: Owen Duffy Subject: Re: Antenna gain question Message-ID: References: Date: Wed, 02 Nov 2005 00:52:01 GMT On Wed, 02 Nov 2005 00:26:06 GMT, Cecil Moore wrote: >Jim Kelley wrote: >> ... what does that have to do with >> "coherently summing all the rays by rotating the antenna"? Just wondering. > >"Coherently summing" certainly doesn't imply that interference >is only constructive. An antenna is "coherently summing" all >the rays it receives no matter what direction it is pointed. Has someone got a good definition of coherent. I thought that it implied "same phase", as in a coherent source is one where all rays, photons, whatever are in phase. An antenna may well receive rays from a single source that are not in phase. If that is the case, what is "coherent summing". Is it trying to refer to a function that adds components algebraically, ie having regard for the magnitude and phase? Why is light a better vehicle for explanation of an antenna that radio waves? Owen -- Article: 218962 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Antenna gain question Date: Tue, 01 Nov 2005 18:59:06 -0800 Message-ID: <11mgarr7utkaj62@corp.supernews.com> References: Owen Duffy wrote: > > Has someone got a good definition of coherent. > > I thought that it implied "same phase", as in a coherent source is one > where all rays, photons, whatever are in phase. An antenna may well > receive rays from a single source that are not in phase. > . . . The way I've always seen it used in this context is meaning "exactly the same frequency". They don't have to be in phase, but the same-frequency requirement implies that the phase relationship wouldn't change with time. This is consistent with the definition from _Merriam Webster's Collegiate Dictionary_: "relating to or composed of waves having a constant difference in phase <~light>". Roy Lewallen, W7EL Article: 218963 of rec.radio.amateur.antenna From: "Caveat Lector" References: Subject: Re: Need antenna article from Ham Radio Mag - Oct 1968 Message-ID: Date: Tue, 1 Nov 2005 19:09:35 -0800 "Caveat Lector" wrote in message news:BBR9f.15969$i%.5959@fed1read07... > > Am posting this for a local ham - W6HPH, Fred > > Do not e-mail me or respond here please -- e-mail Fred direct at > Brown Fred > > Fred asked: > "Do you know anyone who has back issues of Ham Radio ? > > I promised FP5BU a copy of my antenna article which > was in Ham Radio for October 1968 and reprinted in Ham > Radio Horizons for May 1978 and I don't have a copy of > either one. I just want to make a copy of my article > to send to him." > > 73, > Fred, W6HPH > > -- > CL -- I doubt, therefore I might be ! > Golly within hours of this post someone came forward with the article -- wow Thanks folks -- CL -- I doubt, therefore I might be ! Article: 218964 of rec.radio.amateur.antenna Message-ID: <43683106.A6993A2E@shaw.ca> From: Irv Finkleman Subject: How To Put Up An Antenna Date: Wed, 02 Nov 2005 03:22:41 GMT Got this by e-mail from unknown source -- Thought it belongs here... Please don't shoot the messenger! ---------------------------------------- How to install an antenna Here is another letter from Elmer A. Hamoprater titled "how 2 put up an antenner" Please note that we did not correct his spelling or edit his letter in any way. Our Spell Check program crashes when used on Elmer's letters! It is printed here below exactly as sent to us! hay agin mi ham raydio frend. lik i pramised bfor hear is mi letur tellin ya how 2 put up an antenner. tha first theng i need ta say is it shor is hard wurk puttin up an antenner. ya need a lota plannin an fixin bfor ya can git starded. 2 of tha mos emportent thengs ta hav is a gud test dawg ana gud pare uf wyre cuters.. mi test dawges name is yep. i named hem that caws thates whut he duz whin he fines tha wrong wyre fur mi antenner. i ownly use won kind uf antenner wyre caws i kin fine it purty esey arond whur i liv. it downt cost me nuttin ecept fur all tha wawkin an runnin me an yep mi dawg gota du. we start kinda earlie en tha mornin hikin over tha hill tu mi naybors land wher i git tha wyre fur mi antenner. mi naybors gota lota land whur he kepes hes couws an won bull fenced en. an all tha wey arond it on tha fence he keeps nyce nue shiny wyre thet i make mi antenners owt uf. i kin awl ways git awl tha wyre i need thayer caws ever tyme i git sum mi naybor puts mor up betwen tha post. i al so git mi ensulayters frum ofa tha posts ta use own mi antenners. gettin this wyre kin be awful dangrous to yur helth caws uf tha bull so ya gota keepa sharp lookowt furim. bout tha tyme we git closeta tha fence i needa little forta fyin sow i reech bak in mi bak pac and pul owt o i for got to tel ya bout tha bac pac. bfor i leve mi shak i git mi ol ladiy to pac me an yep up sumpin to eet an drenk. wel i git mi dawg yep a biskit an im sorta thirstee sow owt she cums mi jar uf sippin licker. i no im gonna needa lota corage ta git tha wyre owt frum unner that bulls nose sow i opener up and take abowt 8 swallers. mi dowg yep es lookin up at tha jar sow i no he mus be needin a liddle corage 2 sow i reech bak in mi bac pac pull owt anuther biskit and soke it gud withe the sippin whicker an givit toim. doun it gos weth won gulpe ana coupla sekons latur bothe ears stan strate up an i no mi dawg es rediy to wurk. he trots ovur ta tha furst post he cums tu hikes hes hin lig an letser fli. if he lets owt a yep an is nocked backards then i no thet tha wyre is hot ans tha wrong wyre fer mi antenner. this is why its emportunt ta hava gud test dawg. yeps name sure is fittin fer im. whin yep finaly stops yeppin an gits up we go ta a difrunt part uf tha fense and yep dum ol dawg testes it agin. thes tyme he jus sorta luoks at me an grins an i no tha wyre is gud wire fur my antenner. smart dawg mi yep. i reech out an kut tha wyre weth mi wyre cuters an grabit an me an ol yep start runnin as hard as we kin tawards home hopein tha bull was busy. sumtymes i git forti er fity fut ata tyme lik thes. we finely git tu tha shak an ol yep plops doun on tha botum step an i pul ouwt my jar uf swippin clicker an biskits an set a spell wunderin how ime gonna git mi nu wyre up in tha trees. im knot tu keen on climin trees or enything vury hi but ol yep jest luvs ta clime. he wun a contest a while bak at tha cownty fare fer climin an beet dawgs frum al ovor tha place. i now had an idear abowt how to git mi nu wyre up in tha tree sow i maid up mi mind tu let yep hav sume fun sow i wokeim up. he jumped up weth won ear up an won doun an starded ta wag his tayal. i think he new what wus gonna happin. smart dawg mi yep. i got tha nu wyre an tyed it tu his tayal an poyned tu tha tree an yelled up yep an he lit owt lyke greezed litenin up tha syde uf tha tree weth bark justa fliyin. he got abowt tin fut up an straduled tha furst lim an held own an barked doun at me. i new whut he wantid. mor corage. i ran an got anuther biskit an soked it gud frum mi jar an chunked it up tuim. he cawt it in mid air an swollered it hole an ina flash he wuz own hes way agin. i recon tha tree musta ben abowt therty er forety fut tall an yep brok alota lims own his way up tu tha top. he finaliy got tu tha last lim at tha top an grabed hold weth bowth paws an hunge own fer deer lyfe. he wuz sum syte hangin frum tha lim way up ther weth mi nu antenner wyre tyed tu his tayal. wel it jest kame tu me thet ol yep wuz a gud tree climin dawg but thare wuz 1 problem i had fergot. he did ent no how ta git doun. dum dawg mi yep. wel i did ent wont im ta fall sow up tha tree i wint after i fenished mi jar of sippin slisker caws i waddent tu keen on climin.. when i reeched him i tuk tha nu wyre ofa his tayal an tyed it tu tha lim an grabed him an put him arown mi nek an starded doun tha tree. i got tu tha growne an ol yep leeped frum mi bak an ran unner tha shak. smart dawg mi yep. i loked up at mi bran nu antenner wyre hangin frum tha tallist tree i had an then i real lized that tha end uf it wuz abowt therty fuut up tha tree. dang it. here yep. whure is zat dawg. it shor is hard wurk puttin up an antenner. ey will right mor latur whin i git anuther pen -- -------------------------------------- Diagnosed Type II Diabetes March 5 2001 Beating it with diet and exercise! 297/215/210 (to be revised lower) 58"/43"(!)/44" (already lower too!) -------------------------------------- Visit my HomePage at http://members.shaw.ca/finkirv/index.html Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/index.htm Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/index.htm -------------------- Irv Finkleman, Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP Calgary, Alberta, Canada Article: 218965 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Antenna gain question References: Message-ID: Date: Wed, 02 Nov 2005 04:13:28 GMT Jim Kelley wrote: > And still, rotating the antenna has nothing to do with summing the > signals - coherently, or otherwise. Agreed? Are we talking normal operation or receiving big bang background radiation? -- 73, Cecil http://www.qsl.net/w5dxp Article: 218966 of rec.radio.amateur.antenna From: "RST Engineering" Subject: Re: Copper tape antenna element-model Date: Tue, 1 Nov 2005 20:21:48 -0800 Message-ID: <11mgfn0lhhma2be@corp.supernews.com> References: <1130885403.965041.212270@g49g2000cwa.googlegroups.com> Half the width as a first approximation. Jim wrote in message news:1130885403.965041.212270@g49g2000cwa.googlegroups.com... > Hi, I just aquired some 1/4" and 1/2" copper tape that is solderable. > Thinking about using as antenna elements in VHF yagi, UHF TV antenna as > well as other things. Question: When modelling, what wire diameter do > you use when the element is actually conductive tape? Thanks. > Gary N4AST > Article: 218967 of rec.radio.amateur.antenna From: Ron Subject: Re: Antenna gain question References: <11mg31e85kqoa98@corp.supernews.com> Message-ID: <4QW9f.1029$Ea3.137638@twister.southeast.rr.com> Date: Wed, 02 Nov 2005 03:58:56 GMT Roy Lewallen wrote: > Ron wrote: > >> . . . > > >> An isotropic antenna placed at the focal point would collect all of >> the rays whereas a directional antenna at would not. > > >> >> Therefore, in this particular situation, the isotropic would have >> higher gain and capture more power than any directional antenna. >> >> Please correct me if I am wrong. >> > > Not sure what you mean by "focal point", but the best any antenna can do > is to intercept half the energy in some equivalent cross-sectional area > of an impinging field. It does this when connected to a matched load. I agree. By "focal point" I meant the center of the sphere where the rays converge and where the antenna would be located. > When an antenna intercepts one watt from a field having a power density > of one watt per square meter, it's said to have an "effective aperture" > or "capture area" of one square meter. The higher the gain of an antenna > in some particular direction, the larger its effective aperture in that > direction. Consequently, a high gain antenna would "capture" more power > from a wave arriving in its favored direction than an isotropic antenna > would. It would, of course, capture less from other directions, but > assuming equal efficiency, both antennas would capture equal amounts > overall. In the unusual field defined in my example, the algebraic sum of all the rays collected by the antenna would be higher in the isotropic antenna than a high gain antenna. Think of the front to back ratio of the high gain antenna which would result in very little output from the rays behind and on the sides of the antenna. Therefore, the isotropic would have a higher output which is indicative of higher gain. I do not understand what you mean by "capture equal amounts overall". Energy which may strike the antenna but does not result in any output power isn't "captured". > The "capture area" isn't some physical region with boundaries -- it's > simply a way of expressing how much power is extracted from a field > having a given power density. In other words, it's just another way of > expressing antenna gain. How about a dish antenna? Isn't the capture area proportional to the physical area of the dish? Ron, W4TQT Article: 218968 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Antenna gain question References: Message-ID: Date: Wed, 02 Nov 2005 04:30:16 GMT Owen Duffy wrote: > Has someone got a good definition of coherent. From the IEEE Dictionary: "coherent (1)(fiber optics) Characterized by a fixed phase relationship between points on an electromagnetic wave ... (2)(laser maser) A light beam is said to be coherent when the electric vector at any point in it is related to that at any other point by a definite, continuous sinusoidal function." > An antenna may well > receive rays from a single source that are not in phase. I receive rays from WTAW that are sometimes in phase and sometimes not over a period of mere seconds. Earth's atmosphere seems to be a coherence killer. -- 73, Cecil http://www.qsl.net/w5dxp Article: 218969 of rec.radio.amateur.antenna From: Owen Duffy Subject: Re: Antenna gain question Message-ID: References: Date: Wed, 02 Nov 2005 04:41:11 GMT On Wed, 02 Nov 2005 04:30:16 GMT, Cecil Moore wrote: >Owen Duffy wrote: >> Has someone got a good definition of coherent. > > From the IEEE Dictionary: "coherent (1)(fiber optics) Characterized by >a fixed phase relationship between points on an electromagnetic wave ... >(2)(laser maser) A light beam is said to be coherent when the electric >vector at any point in it is related to that at any other point by a >definite, continuous sinusoidal function." > Thanks Cecil and Roy... obviously my understanding (in-phase) was just too narrow. I did find Roy's text more coherent! Interesting to Google for the use of the term, and it appears to be very loosely used... I guess to some extent because of its roots in common language and the ordinary meaning of the word. Owen -- Article: 218970 of rec.radio.amateur.antenna From: Owen Duffy Subject: Re: Antenna gain question Message-ID: References: <11mg31e85kqoa98@corp.supernews.com> <4QW9f.1029$Ea3.137638@twister.southeast.rr.com> Date: Wed, 02 Nov 2005 04:43:34 GMT On Wed, 02 Nov 2005 03:58:56 GMT, Ron wrote: > >In the unusual field defined in my example, the algebraic sum of all >the rays collected by the antenna would be higher in the isotropic >antenna than a high gain antenna. Think of the front to back ratio of >the high gain antenna which would result in very little output from >the rays behind and on the sides of the antenna. Therefore, the >isotropic would have a higher output which is indicative of higher gain. > Is this to rewrite the principle of reciprocity? Owen -- Article: 218971 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Antenna gain question References: <11mg31e85kqoa98@corp.supernews.com> <4QW9f.1029$Ea3.137638@twister.southeast.rr.com> Message-ID: Date: Wed, 02 Nov 2005 04:50:23 GMT Ron wrote: > In the unusual field defined in my example, the algebraic sum of all the > rays collected by the antenna would be higher in the isotropic antenna > than a high gain antenna. The same amount of energy is incident upon both antennas at the center of the sphere. Maybe the high-gain antenna re- radiates more energy than the isotropic? -- 73, Cecil http://www.qsl.net/w5dxp Article: 218972 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: Antenna gain question Date: Wed, 2 Nov 2005 01:39:12 -0600 Message-ID: <16584-43686D20-1259@storefull-3254.bay.webtv.net> References: <11mgarr7utkaj62@corp.supernews.com> Roy, W7EL wrote: "They don`t have to be in phase, but the same frequency requirement implies that the phase relationship wouldn`t change with time." Definitions of terms like "coherent" change with time. Slectromagnetic waves are described as "plane-polarized waves" because variations in their electric and magnetic fields can be represented by vectors that lie in a plane. It is proven that light waves and radio waves are of the same sort but differ in frequency. The first reference I ever saw of a coherent wave was a description of light from a laser. It meant the waves started and stopped together passing through zero at the same time. Light waves are emitted by molecules or atoms that are excited by thermal or electrical means. These molecules or atoms are randomly positioned and so are the waves generated by the energy level changes within them. Phase and polarization are thus random in light produced by ordinary light sources. Light is coherent from a laser. A photon can interact with an atom in a laser if its energy exactly matches the energy difference (delta E) between two allowed (by Bohr) energy states for the atom, it can cause a transition. This is called a stimulated transition. Best regards, Richard Harrison, KB5WZI Article: 218973 of rec.radio.amateur.antenna From: Ron Subject: Re: Antenna gain question References: <11mg31e85kqoa98@corp.supernews.com> <4QW9f.1029$Ea3.137638@twister.southeast.rr.com> <11mgt4u10s0ss67@corp.supernews.com> Message-ID: <7_3af.1056$Ea3.175440@twister.southeast.rr.com> Date: Wed, 02 Nov 2005 14:24:03 GMT Thanks, Roy for your and everyone's participation. I think I will bow out here also. Hope all this hasn't been a waste of space. "Thinking" usually has some value. Ron W4TQT Roy Lewallen wrote: > Ron wrote: > >> . . . >> By "focal point" I meant the center of the sphere where the rays >> converge and where the antenna would be located. > > > I have to admit, I was looking at this a more of a problem of equal > signals arriving from all directions, rather than at the middle of some > sort of convergence. Of course, any rays reaching the center would > continue on through, Cecil's unique theories notwithstanding. I don't > have the spare time to contemplate what the end field distribution would > be like at the center of the antenna or its periphery. > >>> When an antenna intercepts one watt from a field having a power density >>> of one watt per square meter, it's said to have an "effective aperture" >>> or "capture area" of one square meter. The higher the gain of an antenna >>> in some particular direction, the larger its effective aperture in that >>> direction. Consequently, a high gain antenna would "capture" more power >>> from a wave arriving in its favored direction than an isotropic antenna >>> would. It would, of course, capture less from other directions, but >>> assuming equal efficiency, both antennas would capture equal amounts >>> overall. >> >> >> >> In the unusual field defined in my example, the algebraic sum of all >> the rays collected by the antenna would be higher in the isotropic >> antenna than a high gain antenna. > > > It's not obvious to me why that would be. > >> Think of the front to back ratio of the high gain antenna which would >> result in very little output from the rays behind and on the sides of >> the antenna. > > > That's true. But the output would be higher in reponse to the rays > arriving from the front. We call that "gain". Another way to express it > is that it intercepts a field from a larger area of the wave front. > >> Therefore, the isotropic would have a higher output which is >> indicative of higher gain. > > > You're right that higher output means higher gain. I maintain that both > antennas have the same total gain, i.e., the same total interception of > power from all directions. This follows directly from the reciprocity > principle. > >> I do not understand what you mean by "capture equal amounts overall". >> Energy which may strike the antenna but does not result in any output >> power isn't "captured". > > > The field you're creating comes from something and goes somewhere. If > you subtract the total amount going from the total amount generated, > you'll get the amount dissipated in the load connected to the antenna. > That is the amount of energy "captured" or "intercepted" by the antenna. > And that's what I thought you were talking about all along. > >>> The "capture area" isn't some physical region with boundaries -- it's >>> simply a way of expressing how much power is extracted from a field >>> having a given power density. In other words, it's just another way >>> of expressing antenna gain. >> >> >> >> How about a dish antenna? Isn't the capture area proportional to the >> physical area of the dish? > > > Indeed it is, in the front direction. But how about a dipole? The > capture area (or gain) broadside to an infinitesimal dipole is just > slightly less than that of a half wavelength dipole. And wire diameter > makes almost no difference. > > Sorry, the theoretical construct is just a little too much like > Calvinball to hold my interest. I'll bow out now. Best luck in sorting > it out. > > Roy Lewallen, W7EL Article: 218974 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Antenna gain question References: <11mg31e85kqoa98@corp.supernews.com> <4QW9f.1029$Ea3.137638@twister.southeast.rr.com> <11mgt4u10s0ss67@corp.supernews.com> Message-ID: Date: Wed, 02 Nov 2005 15:59:43 GMT Roy Lewallen wrote: > Of course, any rays reaching the center would > continue on through, Cecil's unique theories notwithstanding. The way the incoming fields were defined, they all converge at a point in the center of the sphere. Presumably, that's where the isotropic antenna is located. Replacing the isotropic with a Yagi whose feedpoint is logically located at the point of convergence means that any part of the field that doesn't encounter parts of the Yagi before the point of convergence will converge at the feedpoint on the driven element of the Yagi in a defaulting isotropic manner. Given the definition of the spherical fields, there is no part of the fields that will not encounter the Yagi. Therefore, the isotropic and the Yagi receive the same amount of energy, i.e. all that exists in the spherical fields. Any energy not received by the Yagi beam elements is received in a default- isotropic mode at the Yagi feedpoint. -- 73, Cecil http://www.qsl.net/w5dxp Article: 218975 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: Antenna gain question Date: Wed, 02 Nov 2005 09:38:11 -0800 Message-ID: References: Cecil Moore wrote: > Jim Kelley wrote: > >> And still, rotating the antenna has nothing to do with summing the >> signals - coherently, or otherwise. Agreed? > > > Are we talking normal operation or receiving big > bang background radiation? The source of radiation was not described; only its distribution. It was like being surrounded isotropically by radio sources - not unlike the 3 K background. But there are other sources which pretty well surround us as well. ac6xg Article: 218976 of rec.radio.amateur.antenna From: "Charlie" Subject: Asking for owner comments - LDG AT-1000 Auto Tuner Date: Wed, 2 Nov 2005 11:54:27 -0600 Message-ID: <11mhvb13vr19o31@news.supernews.com> I would like to hear from owners of this auto tuner about any operating quirks / hints / tips. Mine arrives tomorrow and while I have already downloaded and devoured the manual there is nothing quite like hearing straight from other hams. I have read the eHam reviews but still would like to hear more remarks.. TY -- Charlie-AD5TH www.ad5th.com Article: 218977 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <11m6ctlaj9568f9@corp.supernews.com> <1130697713.178097.190440@g43g2000cwa.googlegroups.com> <545am11jsm295ddpo588v5nbtj0u4tedo9@4ax.com> <1130716250.857903.226190@g43g2000cwa.googlegroups.com> <1130780109.071745.6290@g14g2000cwa.googlegroups.com> <1130814155.062907.243770@g43g2000cwa.googlegroups.com> <8e7em1p6p5hbqocd13u7br8a0rupss47kg@4ax.com> Subject: Re: Antenna gain question Date: Wed, 2 Nov 2005 13:09:42 -0500 Message-ID: <7aea1$43690143$97d56a33$20085@ALLTEL.NET> But what if it was rented from Avis? "Richard Clark" wrote in message > specific, then yes the car will radiate by the same principle at > 5 zetta-yottaHertz > > 73's > Richard Clark, KB7QHC Article: 218978 of rec.radio.amateur.antenna From: "Steve Nosko" Subject: Re: ICOM Band Decoder...I found it Date: Wed, 2 Nov 2005 11:56:39 -0600 Message-ID: References: <1130174597.371939.252270@g43g2000cwa.googlegroups.com> I knew I had this, but couldn't find it when I read the post then when I found it, I couldn't remember where I saw the question. I found it, I found it: Icoms have the same voltage that Cecil refers to and here is a "decoder". I believe it identifies all pre-WARC _and_ WARC bands except 12 meters (the rationale being that antenna tuners typically can tune 10 & 12 with the same components). http://www.k6xx.com/radio/icbsciv.html 73, Steve, K;9.D,C.I "gb" wrote in message news:nridnVSM3_pj7sDeRVn-tw@comcast.com... > "Dave" wrote in message > news:1130174597.371939.252270@g43g2000cwa.googlegroups.com... > > Howdy...I am interested in building a cheap and easy band decoder for > > an icom 706mkIIg that will ultimately be used for switching relays on a > > remote antenna switch. I have searched around and found a few people > > that make them and offer kits, but would like to see if anyone has > > built one with good results. Any help or ideas would greatly be > > appreciated... > > > > Thanks, > > > > Dave > > > Elecraft also has a kit -- look at the KRC2 kit .... should offer everything > you want ... Elecraft mail reflector has many happy builders. > http://www.elecraft.com/KRC2/krc2.htm > > w9gb > > > Article: 218979 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Antenna gain question References: Message-ID: Date: Wed, 02 Nov 2005 19:12:12 GMT Jim Kelley wrote: > > Cecil Moore wrote: >> Are we talking normal operation or receiving big >> bang background radiation? > > The source of radiation was not described; only its distribution. It > was like being surrounded isotropically by radio sources - not unlike > the 3 K background. But there are other sources which pretty well > surround us as well. OK, sometimes I lose the context. If the radiation is arriving isotopically, it doesn't matter which direction the Yagi is pointed (as I inferred from what you said). But arriving isotropic radiation would all converge at a point. If a plumber's delight Yagi driven element is centered on that point, it would receive all the radiation in a default-isotropic mode. -- 73, Cecil http://www.qsl.net/w5dxp Article: 218980 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: Antenna gain question Date: Wed, 2 Nov 2005 13:27:21 -0600 Message-ID: <10021-43691319-42@storefull-3251.bay.webtv.net> References: <4QW9f.1029$Ea3.137638@twister.southeast.rr.com> Ron, W4TQT wrote: "How about a dish antenna?" The parabolic reflector converts the spherical waves of its radiator at the focus of the parabola into a plane wave of uniform phase across the mouth or aperture of the parabola. Mouth ans aperture are syninymous when applied to parabolic, lens, and horn antennas. Rays enter and exit parallel but reflect through the focal point. Reciprocity rules and the path through the antenna is the same, coming or going. The parabolic reflector antenna sends and receives to and from a familiar spot on its axis and at a distance. It is inoperative outside the spot and its path of travel. The larger the parabola, the smaller the diameter of the spot, and the higher the power gain. The beamwidth of a large circular aperture such as a parabolic antenna is inversely proportional to its diameter in wavelengths. The total field radiated by a arabola is the vector sum of the fields generated by the elementary areas making up the aperture or mouth of the parabola. The directive gain of a parabola antenna is directly proportional to the area of its mouth and inversely proportional to the wavelength squared. See 1955 Terman page 899, equation (23-28) as pointed out at the bottom of page 911. Best regards, Richard Harrison, KB5WZI Article: 218981 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: Antenna gain question Date: Wed, 02 Nov 2005 11:40:39 -0800 Message-ID: References: Cecil Moore wrote: > Jim Kelley wrote: > >> >> Cecil Moore wrote: >> >>> Are we talking normal operation or receiving big >>> bang background radiation? >> >> >> The source of radiation was not described; only its distribution. It >> was like being surrounded isotropically by radio sources - not unlike >> the 3 K background. But there are other sources which pretty well >> surround us as well. > > > OK, sometimes I lose the context. If the radiation is arriving > isotopically, it doesn't matter which direction the Yagi is > pointed (as I inferred from what you said). > > But arriving isotropic radiation would all converge at a point. > If a plumber's delight Yagi driven element is centered on that > point, it would receive all the radiation in a default-isotropic > mode. I think Roy pretty well nailed the answer. An interesting result - both antennas producing equal signals. I'd like to check that by comparing a dipole to an isotropic in such a field. I assume the results would be the same. Again, an interesting result. But you both bring some interesting points. ac6xg Article: 218982 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: What is low profile antenna? References: <1130962926.892429.129340@z14g2000cwz.googlegroups.com> Message-ID: Date: Wed, 02 Nov 2005 20:37:09 GMT shuisheng wrote: > I am new to antenna field. Anyboday can explain to me what is low > profile antenna? Many thanks. An underground buried antenna would be an example of a very low-profile antenna. Virtually invisible antennas are another example. Disguised antennas (e.g. flagpoles) are another example. Attic antennas are another example. In general, low-profile antennas are inferior in performance to high-profile (extremely visible) antennas. -- 73, Cecil http://www.qsl.net/w5dxp Article: 218983 of rec.radio.amateur.antenna From: "Caveat Lector" References: <1130962926.892429.129340@z14g2000cwz.googlegroups.com> Subject: Re: What is low profile antenna? Message-ID: Date: Wed, 2 Nov 2005 13:04:50 -0800 An antenna that Ms Clipboard of the Home Owners Ass (ociation) can't see -- CL -- I doubt, therefore I might be ! "shuisheng" wrote in message news:1130962926.892429.129340@z14g2000cwz.googlegroups.com... >I am new to antenna field. Anyboday can explain to me what is low > profile antenna? Many thanks. > Article: 218984 of rec.radio.amateur.antenna From: Owen Duffy Subject: Re: What is low profile antenna? Message-ID: <9acim1t0tlrkajfb4eo9mlecb6tnth1obe@4ax.com> References: <1130962926.892429.129340@z14g2000cwz.googlegroups.com> Date: Wed, 02 Nov 2005 21:37:07 GMT On Wed, 2 Nov 2005 21:09:15 -0000, "Dave" wrote: > >"shuisheng" wrote in message >news:1130962926.892429.129340@z14g2000cwz.googlegroups.com... >>I am new to antenna field. Anyboday can explain to me what is low >> profile antenna? Many thanks. >> > >in addition to the other definitions of 'low profile' it could also refer to Some of those "other definitions" might be better described "low (visual) impact", rather than low profile. >a thin aerodynamic antenna such as the patch antennas and other designs used >for car roofs for satellite reception or on aircraft where air flow is >critical. Sounds good. Owen -- Article: 218985 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: Antenna gain question Date: Wed, 2 Nov 2005 16:34:20 -0600 Message-ID: <9037-43693EEC-230@storefull-3254.bay.webtv.net> References: <1130956137.585854.67300@o13g2000cwo.googlegroups.com> Miguel Chezzi, LU6ETJ wrote: "In a deep focal point of parabolic dish two antennas are mounted... Which of them does pick up more energy? An antenna with 180 degree beamwidth or a highly directional sntenna with 0.1 degree beamwidth (both pointed to dish, of course)?" I`ll risk being the fool. We sometimes test for illumination of a reflector. We would not be concerned were it not advantageous to do so. With 180-degree radiation, we fill the dish, using all its surface. With 0.1-degree illumination, we might as well remove all but the illuminated area. It would save dead load and wind loading. My answer: The 180-degree radiation angle will receive a larger area of the plane-wavefront and extract more watts from the wave with a given number of watts per square area. Best regards, Richard Harrison, KB5WZI Article: 218986 of rec.radio.amateur.antenna From: "Hal Rosser" References: <43683106.A6993A2E@shaw.ca> Subject: Re: How To Put Up An Antenna Message-ID: <_vbaf.30193$wG.6142@bignews4.bellsouth.net> Date: Wed, 2 Nov 2005 18:00:15 -0500 "Irv Finkleman" wrote in message news:43683106.A6993A2E@shaw.ca... > Got this by e-mail from unknown source -- Thought it belongs here... > Please don't shoot the messenger! > ---------------------------------------- > How to install an antenna > > Here is another letter from Elmer A. Hamoprater titled > "how 2 put up an antenner" > > Please note that we did not correct his spelling or edit his letter in any way. > Our Spell Check program crashes when used on Elmer's letters! > It is printed here below exactly as sent to us! > hay agin mi ham raydio frend. > lik i pramised bfor hear is mi letur tellin ya how 2 put up an > antenner. > tha first theng i need ta say is it shor is hard wurk puttin up an > antenner. > ya need a lota plannin an fixin bfor ya can git starded. > 2 of tha mos emportent thengs ta hav is a gud test dawg ana gud pare > uf wyre cuters.. > mi test dawges name is yep. > i named hem that caws thates whut he duz whin he fines tha wrong wyre > fur mi antenner. > i ownly use won kind uf antenner wyre caws i kin fine it purty esey > arond whur i liv. > it downt cost me nuttin ecept fur all tha wawkin an runnin me an yep > mi dawg gota du. > we start kinda earlie en tha mornin hikin over tha hill tu mi > naybors land > wher i git tha wyre fur mi antenner. > mi naybors gota lota land whur he kepes hes couws an won bull > fenced en. > an all tha wey arond it on tha fence he keeps nyce nue shiny wyre thet i > make mi antenners owt uf. > i kin awl ways git awl tha wyre i need thayer caws ever tyme i git sum > mi naybor puts mor > up betwen tha post. > i al so git mi ensulayters frum ofa tha posts ta use own mi > antenners. > gettin this wyre kin be awful dangrous to yur helth caws uf tha bull so ya > gota keepa sharp lookowt furim. > bout tha tyme we git closeta tha fence i needa little forta fyin sow i reech > bak in mi bak pac and pul owt > o i for got to tel ya bout tha bac pac. > bfor i leve mi shak i git mi ol ladiy to pac me an yep up sumpin to > eet an drenk. > wel i git mi dawg yep a biskit an im sorta thirstee sow owt she cums > mi jar uf sippin licker. > i no im gonna needa lota corage ta git tha wyre owt frum unner that bulls nose > sow i opener up and take abowt > 8 swallers. > mi dowg yep es lookin up at tha jar sow i no he mus be needin a liddle corage > 2 sow i reech bak in mi bac pac > pull owt anuther biskit and soke it gud withe the sippin whicker an > givit toim. > doun it gos weth won gulpe ana coupla sekons latur bothe ears stan strate up > an i no mi dawg es rediy to wurk. > he trots ovur ta tha furst post he cums tu hikes hes hin > lig an letser fli. > if he lets owt a yep an is nocked backards then i no thet tha wyre is hot ans > tha wrong wyre fer mi antenner. > this is why its emportunt ta hava gud test dawg. > yeps name sure is fittin fer im. > whin yep finaly stops yeppin an gits up we go ta a difrunt part uf tha fense > and yep dum ol dawg testes it agin. > thes tyme he jus sorta luoks at me an grins an i no tha wyre is gud wire fur > my antenner. smart dawg mi yep. > i reech out an kut tha wyre weth mi wyre cuters an grabit an me an ol yep start runnin > as hard as we kin tawards home hopein tha bull > was busy. sumtymes i git forti er fity fut ata tyme lik > thes. > we finely git tu tha shak an ol yep plops doun on tha botum step an i pul > ouwt my jar uf swippin clicker an > biskits an set a spell wunderin how ime gonna git mi nu wyre up in > tha trees. > im knot tu keen on climin trees or enything vury hi but ol yep jest luvs ta > clime. he wun a contest a while bak at > tha cownty fare fer climin an beet dawgs frum al ovor tha > place. > i now had an idear abowt how to git mi nu wyre up in tha tree sow i maid up mi mind > tu let yep hav sume fun sow i wokeim up. > he jumped up weth won ear up an won doun an starded ta wag his tayal. i think > he new what wus gonna happin. > smart dawg mi yep. > i got tha nu wyre an tyed it tu his tayal an poyned tu tha tree an yelled up > yep an he lit owt lyke greezed > litenin up tha syde uf tha tree weth bark justa fliyin. > he got abowt tin fut up an straduled tha furst lim an held own an > barked doun at me. > i new whut he wantid. mor corage. > i ran an got anuther biskit an soked it gud frum mi jar an chunked > it up tuim. > he cawt it in mid air an swollered it hole an ina flash he wuz own > hes way agin. > i recon tha tree musta ben abowt therty er forety fut tall an yep brok alota > lims own his way up tu tha top. > he finaliy got tu tha last lim at tha top an grabed hold weth bowth paws > an hunge own fer deer lyfe. > he wuz sum syte hangin frum tha lim way up ther weth mi nu antenner wyre > tyed tu his tayal. > wel it jest kame tu me thet ol yep wuz a gud tree climin dawg but thare > wuz 1 problem i had fergot. > he did ent no how ta git doun. > dum dawg mi yep. > wel i did ent wont im ta fall sow up tha tree i wint after i fenished mi jar of > sippin slisker caws i waddent tu keen > on climin.. > when i reeched him i tuk tha nu wyre ofa his tayal an tyed it tu tha lim > an grabed him an put > him arown mi nek an starded doun tha tree. > i got tu tha growne an ol yep leeped frum mi bak an ran unner tha > shak. > smart dawg mi yep. > i loked up at mi bran nu antenner wyre hangin frum tha tallist tree i had > an then i real lized that > tha end uf it wuz abowt therty fuut up tha tree. > dang it. > here yep. whure is zat dawg. > > it shor is hard wurk puttin up an antenner. > > ey will right mor latur whin i git anuther pen > -- > -------------------------------------- > Diagnosed Type II Diabetes March 5 2001 > Beating it with diet and exercise! > 297/215/210 (to be revised lower) > 58"/43"(!)/44" (already lower too!) > -------------------------------------- > Visit my HomePage at http://members.shaw.ca/finkirv/index.html > Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/index.htm > Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/index.htm > -------------------- > Irv Finkleman, > Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP > Calgary, Alberta, Canada Article: 218987 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: Antenna gain question Date: Wed, 02 Nov 2005 15:18:02 -0800 Message-ID: References: <1130956137.585854.67300@o13g2000cwo.googlegroups.com> <9037-43693EEC-230@storefull-3254.bay.webtv.net> Richard Harrison wrote: > Miguel Chezzi, LU6ETJ wrote: > "In a deep focal point of parabolic dish two antennas are mounted... > > Which of them does pick up more energy? > An antenna with 180 degree beamwidth or a highly directional sntenna > with 0.1 degree beamwidth (both pointed to dish, of course)?" > > I`ll risk being the fool. We sometimes test for illumination of a > reflector. We would not be concerned were it not advantageous to do so. > > With 180-degree radiation, we fill the dish, using all its surface. > With 0.1-degree illumination, we might as well remove all but the > illuminated area. It would save dead load and wind loading. > > My answer: The 180-degree radiation angle will receive a larger area of > the plane-wavefront and extract more watts from the wave with a given > number of watts per square area. > > Best regards, Richard Harrison, KB5WZI The question you have to ask yourself is, does it intercept all of the energy reflected toward it, or only some fraction of it. We should always be cognizant of the limits imposed by the absence of a free lunch. ac6xg Article: 218988 of rec.radio.amateur.antenna From: "Hal Rosser" References: <43683106.A6993A2E@shaw.ca> Subject: Re: How To Put Up An Antenna Message-ID: Date: Wed, 2 Nov 2005 18:28:16 -0500 That reminds me of a story that used to circulate about the ham writing a letter to the insurance company explaining how he incurred his injuries while working on his antenna tower. Something about: 300 lbs of tools in a bucket at the top of the tower and the bucket was on a rope that went through a pully at the top of the tower. he weighed only 150 lbs and as he accelerated upward, he forgot to turn loose of the rope met the bucket with his head half way up (and again with his ankles half way down because the bottom fell out of the bucket when it hit the ground ). Does anyone have a link to this original story ? "Irv Finkleman" wrote in message news:43683106.A6993A2E@shaw.ca... > Got this by e-mail from unknown source -- Thought it belongs here... > Please don't shoot the messenger! > ---------------------------------------- > How to install an antenna > > Here is another letter from Elmer A. Hamoprater titled > "how 2 put up an antenner" > > Please note that we did not correct his spelling or edit his letter in any way. > Our Spell Check program crashes when used on Elmer's letters! > It is printed here below exactly as sent to us! > hay agin mi ham raydio frend. > lik i pramised bfor hear is mi letur tellin ya how 2 put up an > antenner. > tha first theng i need ta say is it shor is hard wurk puttin up an > antenner. > ya need a lota plannin an fixin bfor ya can git starded. > 2 of tha mos emportent thengs ta hav is a gud test dawg ana gud pare > uf wyre cuters.. > mi test dawges name is yep. > i named hem that caws thates whut he duz whin he fines tha wrong wyre > fur mi antenner. > i ownly use won kind uf antenner wyre caws i kin fine it purty esey > arond whur i liv. > it downt cost me nuttin ecept fur all tha wawkin an runnin me an yep > mi dawg gota du. > we start kinda earlie en tha mornin hikin over tha hill tu mi > naybors land > wher i git tha wyre fur mi antenner. > mi naybors gota lota land whur he kepes hes couws an won bull > fenced en. > an all tha wey arond it on tha fence he keeps nyce nue shiny wyre thet i > make mi antenners owt uf. > i kin awl ways git awl tha wyre i need thayer caws ever tyme i git sum > mi naybor puts mor > up betwen tha post. > i al so git mi ensulayters frum ofa tha posts ta use own mi > antenners. > gettin this wyre kin be awful dangrous to yur helth caws uf tha bull so ya > gota keepa sharp lookowt furim. > bout tha tyme we git closeta tha fence i needa little forta fyin sow i reech > bak in mi bak pac and pul owt > o i for got to tel ya bout tha bac pac. > bfor i leve mi shak i git mi ol ladiy to pac me an yep up sumpin to > eet an drenk. > wel i git mi dawg yep a biskit an im sorta thirstee sow owt she cums > mi jar uf sippin licker. > i no im gonna needa lota corage ta git tha wyre owt frum unner that bulls nose > sow i opener up and take abowt > 8 swallers. > mi dowg yep es lookin up at tha jar sow i no he mus be needin a liddle corage > 2 sow i reech bak in mi bac pac > pull owt anuther biskit and soke it gud withe the sippin whicker an > givit toim. > doun it gos weth won gulpe ana coupla sekons latur bothe ears stan strate up > an i no mi dawg es rediy to wurk. > he trots ovur ta tha furst post he cums tu hikes hes hin > lig an letser fli. > if he lets owt a yep an is nocked backards then i no thet tha wyre is hot ans > tha wrong wyre fer mi antenner. > this is why its emportunt ta hava gud test dawg. > yeps name sure is fittin fer im. > whin yep finaly stops yeppin an gits up we go ta a difrunt part uf tha fense > and yep dum ol dawg testes it agin. > thes tyme he jus sorta luoks at me an grins an i no tha wyre is gud wire fur > my antenner. smart dawg mi yep. > i reech out an kut tha wyre weth mi wyre cuters an grabit an me an ol yep start runnin > as hard as we kin tawards home hopein tha bull > was busy. sumtymes i git forti er fity fut ata tyme lik > thes. > we finely git tu tha shak an ol yep plops doun on tha botum step an i pul > ouwt my jar uf swippin clicker an > biskits an set a spell wunderin how ime gonna git mi nu wyre up in > tha trees. > im knot tu keen on climin trees or enything vury hi but ol yep jest luvs ta > clime. he wun a contest a while bak at > tha cownty fare fer climin an beet dawgs frum al ovor tha > place. > i now had an idear abowt how to git mi nu wyre up in tha tree sow i maid up mi mind > tu let yep hav sume fun sow i wokeim up. > he jumped up weth won ear up an won doun an starded ta wag his tayal. i think > he new what wus gonna happin. > smart dawg mi yep. > i got tha nu wyre an tyed it tu his tayal an poyned tu tha tree an yelled up > yep an he lit owt lyke greezed > litenin up tha syde uf tha tree weth bark justa fliyin. > he got abowt tin fut up an straduled tha furst lim an held own an > barked doun at me. > i new whut he wantid. mor corage. > i ran an got anuther biskit an soked it gud frum mi jar an chunked > it up tuim. > he cawt it in mid air an swollered it hole an ina flash he wuz own > hes way agin. > i recon tha tree musta ben abowt therty er forety fut tall an yep brok alota > lims own his way up tu tha top. > he finaliy got tu tha last lim at tha top an grabed hold weth bowth paws > an hunge own fer deer lyfe. > he wuz sum syte hangin frum tha lim way up ther weth mi nu antenner wyre > tyed tu his tayal. > wel it jest kame tu me thet ol yep wuz a gud tree climin dawg but thare > wuz 1 problem i had fergot. > he did ent no how ta git doun. > dum dawg mi yep. > wel i did ent wont im ta fall sow up tha tree i wint after i fenished mi jar of > sippin slisker caws i waddent tu keen > on climin.. > when i reeched him i tuk tha nu wyre ofa his tayal an tyed it tu tha lim > an grabed him an put > him arown mi nek an starded doun tha tree. > i got tu tha growne an ol yep leeped frum mi bak an ran unner tha > shak. > smart dawg mi yep. > i loked up at mi bran nu antenner wyre hangin frum tha tallist tree i had > an then i real lized that > tha end uf it wuz abowt therty fuut up tha tree. > dang it. > here yep. whure is zat dawg. > > it shor is hard wurk puttin up an antenner. > > ey will right mor latur whin i git anuther pen > -- > -------------------------------------- > Diagnosed Type II Diabetes March 5 2001 > Beating it with diet and exercise! > 297/215/210 (to be revised lower) > 58"/43"(!)/44" (already lower too!) > -------------------------------------- > Visit my HomePage at http://members.shaw.ca/finkirv/index.html > Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/index.htm > Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/index.htm > -------------------- > Irv Finkleman, > Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP > Calgary, Alberta, Canada Article: 218989 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: How To Put Up An Antenna Date: Wed, 02 Nov 2005 16:24:03 -0800 Message-ID: <11mim54bve97rcc@corp.supernews.com> References: <43683106.A6993A2E@shaw.ca> Hal Rosser wrote: > That reminds me of a story that used to circulate about the ham writing a > letter to the insurance company explaining how he incurred his injuries > while working on his antenna tower. > Something about: 300 lbs of tools in a bucket at the top of the tower and > the bucket was on a rope that went through a pully at the top of the tower. > he weighed only 150 lbs > and as he accelerated upward, he forgot to turn loose of the rope > met the bucket with his head half way up (and again with his ankles half way > down because the bottom fell out of the bucket when it hit the ground ). > > Does anyone have a link to this original story ? The original is almost certainly lost in the mists of time. My dad used to tell me a version of that when I was a little kid. And he probably heard it from his dad. Roy Lewallen, W7EL Article: 218990 of rec.radio.amateur.antenna From: "David G. Nagel" Subject: Re: How To Put Up An Antenna Date: Wed, 02 Nov 2005 18:56:03 -0600 Message-ID: <11mio1h6a2td18f@corp.supernews.com> References: <43683106.A6993A2E@shaw.ca> <11mim54bve97rcc@corp.supernews.com> Roy Lewallen wrote: > Hal Rosser wrote: > >> That reminds me of a story that used to circulate about the ham writing a >> letter to the insurance company explaining how he incurred his injuries >> while working on his antenna tower. >> Something about: 300 lbs of tools in a bucket at the top of the >> tower and >> the bucket was on a rope that went through a pully at the top of the >> tower. >> he weighed only 150 lbs >> and as he accelerated upward, he forgot to turn loose of the rope >> met the bucket with his head half way up (and again with his ankles >> half way >> down because the bottom fell out of the bucket when it hit the ground ). >> >> Does anyone have a link to this original story ? > > > The original is almost certainly lost in the mists of time. My dad used > to tell me a version of that when I was a little kid. And he probably > heard it from his dad. > > Roy Lewallen, W7EL Mythbusters looked into this myth and ircc they found it not only false but impossible. I could be wrong though. Dave WD9BDZ BTW: Glad to see you back Roy... Article: 218991 of rec.radio.amateur.antenna From: dplatt@radagast.org (Dave Platt) Subject: Re: Attn: Dave Platt AE6EO Date: Thu, 03 Nov 2005 02:11:40 -0000 Message-ID: <11miseskpjvlc80@corp.supernews.com> References: In article , Dan Richardson <> wrote: >Dave, > >I have been trying to reach you via email, but your ISP bounced my >message calling it spam (It didn't like my return address). Next I >tried using a different return address and while that message wasn't >bounced I received no reply. So wondering if you could contact me? > >k6mhearrlnet Hi, Dan! I did get your second message on Monday, and replied to it... but a mailer problem on my system ate the outbound mail, alas. The answer to your question is: yes, by all means go ahead and post the link to my page about the Laport book. The only change I'd suggest is purely editorial - there's an extra blank in the "6-by-9- inch softcover" text which could be removed. Otherwise, it looks just fine. Thanks much for being willing to add the link to your antennas page! -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! Article: 218992 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: Antenna gain question Date: Wed, 2 Nov 2005 21:21:59 -0600 Message-ID: <10021-43698257-110@storefull-3251.bay.webtv.net> References: Jim Kelley, AC6XG wrote: "The question you have to ask yourself is, does it intercept all of the energy reflected toward it, or only some fraction of it." Nothing is perfect as Jim observes. "Imperfections" are sometimes exploited to improve an antenna pattern. To a first approximation though, we assume that all the parallel rays intercepted by a dish are focused on the radiator and aid, adding in-phase. Received carrier power excites the antenna and this causes a minimum of 50% of this power to be re-radiated if the antenna is perfectly matched to to the receiver load. The antenna`s radiation resistance in this case becomes the Thevenin`s source resistance for the receiver load on the antenna. This requires a conjugate match between the antenna and receiver input impedances. 50% of the received power to the receiver is the best that can be done under optimum conditions, that is , with a perfect match. With a 100% mismatch, a short-circuit, 100% of the intercepted power is re-radiated by the antenna. If the antenna is open-circuited, it accepts none of the power focused upon it. Best regards, Richard Harrison, KB5WZI Article: 218993 of rec.radio.amateur.antenna From: "the Fords" References: Subject: Re: Source for Butternut Vertical parts Message-ID: Date: Wed, 2 Nov 2005 21:45:37 -0600 Burghardt has many of the parts in stock K5ACO James Ford Article: 218994 of rec.radio.amateur.antenna From: "AAA RF Products" Subject: Coax Cable, Connector & Adapter Catalog available at no charge. Message-ID: Date: Wed, 2 Nov 2005 21:07:57 -0800 Please email sales@aaarfproducts.com for your free copy of our latest catalog, or see www.aaarfproducts.com Article: 218995 of rec.radio.amateur.antenna From: "harrogate2" References: <1130962926.892429.129340@z14g2000cwz.googlegroups.com> Subject: Re: What is low profile antenna? Message-ID: Date: Thu, 03 Nov 2005 08:46:31 GMT "Cecil Moore" wrote in message news:Vr9af.8917$q%.4633@newssvr12.news.prodigy.com... > shuisheng wrote: > > I am new to antenna field. Anyboday can explain to me what is low > > profile antenna? Many thanks. > > An underground buried antenna would be an example of a > very low-profile antenna. Virtually invisible antennas > are another example. Disguised antennas (e.g. flagpoles) > are another example. Attic antennas are another example. > In general, low-profile antennas are inferior in performance > to high-profile (extremely visible) antennas. > -- > 73, Cecil http://www.qsl.net/w5dxp Sorry, absolute blx. You are getting confused with a covert antenna. A low profile antenna is one that is designed not to stick up when vertically polarised, and may at the same time be not visually intrusive. They are most often found (and visible) on the roof of security vans or buses, and look like a small flat-ish upturned dish - for UK hi-band (170MHz) being about 18" across and about 2-3" high. In most applications they are omnidirectional and vertically polarised. Technically they are a slot antenna - a Google search will explain how they work. They have the advantage that the metal fixing base will act as a ground plane so they can be fitted on fibre-glass bodies without worry. They are popular on buses as they don't get pulled off by the vehicle wash. -- Woody harrogate2 at ntlworld dot com Article: 218996 of rec.radio.amateur.antenna From: aRKay Subject: Re: Coax Cable, Connector & Adapter Catalog available at no charge. References: Message-ID: Date: Thu, 03 Nov 2005 11:50:22 GMT In article , "AAA RF Products" wrote: > Please email sales@aaarfproducts.com for your free copy of our latest > catalog, or see www.aaarfproducts.com The real address is http://aaarfproducts.com/ not what is listed above Article: 218997 of rec.radio.amateur.antenna From: HS Subject: Re: Backpack Antenna, help please References: Message-ID: Date: Thu, 03 Nov 2005 13:36:07 GMT 2m antenna? -Simple! Cut a piece of wire, 1/4 wave long. Solder wire to inner lead of the end of a coaxial cable. Find a stick of wood, plastic or fiberglass, at least 3/4 wl long. Tape wire and coax to stick. Fix stick to rucksack, so that the antenna wire is as high as possible. Connect coax to radio. That's it! 73 de Hans, SM3PXG Steve - www.ukspeedtraps.co.uk wrote: > Hi All > > I want to construct a backpack antenna that can be left on my rucksack and > used when walking. > > The plan is to have a FT817 on my waist and the antenna fitted to the > rucksack. I been playing with a mobile antenna today and can not get the SWR > down without trailing a wire. I don't want a wire trailing behind me. > > Any ideas for a 2m antenna that can be left on a rucksack when walking and > used for transmittion. Height is not a major problem but it has to realistic > and robust. > > Thanks > Steve > Article: 218998 of rec.radio.amateur.antenna From: bigamps Subject: Re: Coax Cable, Connector & Adapter Catalog available at no charge. References: Message-ID: Date: Thu, 03 Nov 2005 14:27:38 GMT aRKay wrote: > In article , > "AAA RF Products" wrote: > > >>Please email sales@aaarfproducts.com for your free copy of our latest >>catalog, or see www.aaarfproducts.com > > > The real address is http://aaarfproducts.com/ not what is listed above Both of them worked fine for me and both brought up the same page. Article: 218999 of rec.radio.amateur.antenna From: "W5GT" Subject: Higher antenna? Message-ID: Date: Thu, 3 Nov 2005 08:37:28 -0600 I'm putting up a tower in the next week or so. It will have a TA33. I've been putting up antennas for years, but never with a tower. I know the old adage that you should put up as much aluminum as you can afford as high as you can put it. However, will there be a noticeable difference between 34' and 44'? I work DX and with the declining sunspots, I suspect that on some weak signals it might. Thanks Dave - W5GT Article: 219000 of rec.radio.amateur.antenna From: "W5GT" References: Subject: Re: 1 Section 25G in DFW area Message-ID: Date: Thu, 3 Nov 2005 08:38:42 -0600 Found a section - thanks Dave - W5GT "W5GT" wrote in message news:Fnr9f.7204$7s1.6016@fe04.lga... > I need one section of 25G in the Dallas/Ft Worth area. Please contact me at > w5gt@arrl.net. > > Thanks > > Dave - W5GT > > Article: 219001 of rec.radio.amateur.antenna From: "Bill" References: Subject: Re: Higher antenna? Message-ID: Date: Thu, 3 Nov 2005 10:04:26 -0500 Easy...... At One Wavelength the "spray" on the antenna opens fully........as you raise the antenna the angle of take off lowers......(getting you to your DX station with more apparent power). -In W2PV's bible...the take off angle of a 3 element beam at 1 wl is 14 degrees, raise it to 1.5 WL and now the take off is 9 degrees...go to 2 WL and its 7 degrees. -Now take into consideration the useable angle of propagation, as the angle rises you will begin to use the higher lobes of your antenna. -There are times that because of the very high propagation angle my vertical is stronger than my 5 ele @ 150' and my 4 element at 106' and my multibander at 68'...... Bill http://www.kc4pe.com/amateurshack.htm "W5GT" wrote in message news:zgpaf.55676$RG4.17750@fe05.lga... > I'm putting up a tower in the next week or so. It will have a TA33. > > I've been putting up antennas for years, but never with a tower. I know > the > old adage that you should put up as much aluminum as you can afford as > high > as you can put it. However, will there be a noticeable difference between > 34' and 44'? I work DX and with the declining sunspots, I suspect that on > some weak signals it might. > > Thanks > > Dave - W5GT > > Article: 219002 of rec.radio.amateur.antenna From: N7ZZT - Eric Oyen Subject: Looking for a male-any race is fine Date: Thu, 03 Nov 2005 10:02:57 -0500 Message-ID: <5h9km1h2ud7v4hro4nsdmio0j2ft77rnhl@4ax.com> Hello, I am a swm, 31 years old and blind. I am seeking a male to be my partner. Race is not a particular point here. he must be understanding and intelligent. Interests are hikingm camping, radio, sci-fi and cooking. Since I am relatively new at this (not much experience), I am willing to learn. My social skills are not well honed, so I may be a little rough around the edges. _________________________________________ Usenet Zone Free Binaries Usenet Server More than 140,000 groups Unlimited download http://www.usenetzone.com to open account Article: 219003 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: I Found It! Date: Thu, 3 Nov 2005 09:00:58 -0600 Message-ID: <10023-436A262A-8@storefull-3251.bay.webtv.net> References: <436965C2.CD6E05BC@shaw.ca> Itv Finkleman, VE6BP wrote: "I`ve got a copy of it somewhere on this machine." It was worth waiting for. Many tower crews I`ve worked with had someone who told some version of the tool or bolt bag story, but Irv`s with its rain of bricks strikes me as best of all. 64 years ago I was a member of the Hod Carriers Union, AFL. Best regards, Richard Harrison, KB5WZI Article: 219004 of rec.radio.amateur.antenna From: Bob Bob Subject: Re: 900MHz antenna at sea surface References: <1130962168.655457.263840@f14g2000cwb.googlegroups.com> Message-ID: <2oop33-r9a.ln1@p400bob.personal.cox.net> Date: Thu, 03 Nov 2005 09:59:29 -0600 Hi Jim Along with comments from Dave I thought it might be worth mentioning a few more points. Think of 900MHz as line of sight and any obstruction is an issue to plan for. It is worth keeping the antenna gain low because of wave slap action tilting the structure and radiation pattern. Also consider mounting it as high as you can off the water surface, say a few metres. Hopefully this will allow for the device rolling into a wave trough whilst still giving you reasonable range. The best analogy here is to replace the antenna with a lamp and se how far you can see it from. If you end up needing high antenna gain consider gimballing the antenna to keep it oriented properly. I'd stick to providing the gain at the ship/shore end though. If multipath reflections and cancellations are a problem (and honestly I dont think they are in a water/wave environment - more an issue between trees and buildings) then consider a horizontal antenna like a halo, bent dipole or "3 leaf clover". The plus with a horizontal is that the antenna aperture is wide rather than high so phase cancellations are much less of a problem. You should also consider that what ever data you are sending might be lost periodically so whatever it is make sure there is a forward error correction or retry mechanism where needed. Cheers Bob VK2YQA jmorash wrote: > > thanks for any suggestions > --Jim Morash > Article: 219005 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: 900MHz antenna at sea surface Date: Thu, 3 Nov 2005 10:05:24 -0600 Message-ID: <10021-436A3544-176@storefull-3251.bay.webtv.net> References: <1130962168.655457.263840@f14g2000cwb.googlegroups.com> Jim Morash wrote: "It will be tough to get the antenna more than a foot (maybe two) out of the water." It may be worth the effort for the sake of your hardware. Distance to the horizon in miles is the square root of teice the antenna elevation in feet. Two feet elevation puts the horizon at two miles. 20 feet slevation on the other end of your path extends it by 6 miles. Low obstructions may block a very low path at times as 900 MHz requires a line-of-sight path. You might anchor a buoy to hold your antenna at a convenient height. A 1/2-wave coaxial dipole works about as well as any VHF or UHF antenna on a boat or float. Commercial versions use 1/4-wave of rigid tubing as a skirt over the coax feedline. This tubing is the lower half of the antenna. The upper half is a 1/4-wave whip mounted on the lower half. There are no radials to get in the way or poke out any eyes. Best regards, Richard Harrison, KB5WZI Article: 219006 of rec.radio.amateur.antenna From: "Steve - www.ukspeedtraps.co.uk" Subject: Re: Backpack Antenna, help please Date: Thu, 3 Nov 2005 16:41:34 +0000 (UTC) Message-ID: References: "HS" wrote in message news:bnoaf.149862$dP1.507670@newsc.telia.net... > 2m antenna? > > -Simple! > > Cut a piece of wire, 1/4 wave long. > > Solder wire to inner lead of the end of a coaxial cable. > > Find a stick of wood, plastic or fiberglass, at least 3/4 wl long. > > Tape wire and coax to stick. > > Fix stick to rucksack, so that the antenna wire is as high as possible. > > Connect coax to radio. > > That's it! > > > 73 de Hans, SM3PXG > > Thanks for that, so a 1/4 wave does not need a counterpoise then? Steve Article: 219007 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Backpack Antenna, help please References: Message-ID: Date: Thu, 03 Nov 2005 17:19:29 GMT Steve - www.ukspeedtraps.co.uk wrote: > Thanks for that, so a 1/4 wave does not need a counterpoise then? Strip 1/4WL of insulation from the coax. Fold the outside braid back along the coax. That will leave you 1/4WL of center conductor exposed (you can leave the center insulation in place) and the braid will provide the other half of the antenna which should be insulated to avoid backpacking RF burns. Kraus calls such a "vertical 1/2WL sleeve antenna. On edge it looks like: -------------------+ -------------------------------+ 1/4WL ==================================================== -------------------------------+ -------------------+ 1/4WL -- 73, Cecil http://www.qsl.net/w5dxp Article: 219008 of rec.radio.amateur.antenna From: clvrmnky Subject: Re: Coax Cable, Connector & Adapter Catalog available at no charge. References: Message-ID: Date: Thu, 03 Nov 2005 12:32:25 -0500 On 03/11/2005 6:50 AM, aRKay wrote: > In article , > "AAA RF Products" wrote: > >> Please email sales@aaarfproducts.com for your free copy of our latest >> catalog, or see www.aaarfproducts.com > > The real address is http://aaarfproducts.com/ not what is listed above The hostname ("www") can be left off in most cases when contacting the default web site. Failure to set things up like this on a commercial site is usually considered an error. Article: 219009 of rec.radio.amateur.antenna From: "hasan schiers" Subject: Re: Higher antenna? Date: Thu, 3 Nov 2005 11:34:08 -0600 Message-ID: References: The center of the first lobe's elevation angle can be calculated by: arcsin of (a/4*H), where a=1 and H = the antenna height in wavelengths. Plugging in 34 and 44 feet respectively (after normalizing to wavelengths), will show you how much improvement you are likely to see in reducing the takeoff angle. Keep in mind the TOA is a cone or lobe, not a line. At 14.1 Mhz, a wavelength is approx 69 feet. So 34/69 is .49. The value of H for 20m and 34 feet is .49. The formula then is arcsin of 1/(4*.49)....this will give you the TOA (takeoff angle) for your horizontal antenna at 34'. Do the same calculation for 44' and you will see the TOA is lower. Do the calculation for each band you are interested in. Be sure to calculate the wavelength for each band: 982/f, where f is in Megahertz. BTW, the first null is found by using a=2, the 2nd lobe (if there is one) will be found at a=3, the second null (if there is one) will be found at a=4 You will see these additional lobes and nulls on 10 meters, but not on 20m Hope this helps. 73 ...hasan, N0AN p.s. Every little bit helps if you are a DX'er. "W5GT" wrote in message news:zgpaf.55676$RG4.17750@fe05.lga... > I'm putting up a tower in the next week or so. It will have a TA33. > > I've been putting up antennas for years, but never with a tower. I know > the > old adage that you should put up as much aluminum as you can afford as > high > as you can put it. However, will there be a noticeable difference between > 34' and 44'? I work DX and with the declining sunspots, I suspect that on > some weak signals it might. > > Thanks > > Dave - W5GT > > Article: 219010 of rec.radio.amateur.antenna From: "hasan schiers" Subject: Re: Higher antenna? Date: Thu, 3 Nov 2005 12:19:29 -0600 Message-ID: References: That should have been 984/f, not 982...bad memory. N0AN "hasan schiers" wrote in message news:dkdhmp$d6r$1@news.netins.net... > The center of the first lobe's elevation angle can be calculated by: > > arcsin of (a/4*H), where a=1 and H = the antenna height in wavelengths. > > Plugging in 34 and 44 feet respectively (after normalizing to > wavelengths), will show you how much improvement you are likely to see in > reducing the takeoff angle. > > Keep in mind the TOA is a cone or lobe, not a line. > > At 14.1 Mhz, a wavelength is approx 69 feet. So 34/69 is .49. The value of > H for 20m and 34 feet is .49. The formula then is arcsin of > 1/(4*.49)....this will give you the TOA (takeoff angle) for your > horizontal antenna at 34'. Do the same calculation for 44' and you will > see the TOA is lower. > > Do the calculation for each band you are interested in. Be sure to > calculate the wavelength for each band: > > 982/f, where f is in Megahertz. > > BTW, the first null is found by using a=2, the 2nd lobe (if there is one) > will be found at a=3, the second null (if there is one) will be found at > a=4 > > You will see these additional lobes and nulls on 10 meters, but not on 20m > > Hope this helps. 73 > > ...hasan, N0AN > > p.s. Every little bit helps if you are a DX'er. > > > "W5GT" wrote in message > news:zgpaf.55676$RG4.17750@fe05.lga... >> I'm putting up a tower in the next week or so. It will have a TA33. >> >> I've been putting up antennas for years, but never with a tower. I know >> the >> old adage that you should put up as much aluminum as you can afford as >> high >> as you can put it. However, will there be a noticeable difference between >> 34' and 44'? I work DX and with the declining sunspots, I suspect that on >> some weak signals it might. >> >> Thanks >> >> Dave - W5GT >> >> > > Article: 219011 of rec.radio.amateur.antenna From: "Steve - www.ukspeedtraps.co.uk" Subject: Re: Backpack Antenna, help please Date: Thu, 3 Nov 2005 18:41:00 +0000 (UTC) Message-ID: References: "Cecil Moore" wrote in message news:BEraf.8089$BZ5.4265@newssvr13.news.prodigy.com... > Steve - www.ukspeedtraps.co.uk wrote: >> Thanks for that, so a 1/4 wave does not need a counterpoise then? > > Strip 1/4WL of insulation from the coax. Fold the outside > braid back along the coax. That will leave you 1/4WL of > center conductor exposed (you can leave the center > insulation in place) and the braid will provide the > other half of the antenna which should be insulated > to avoid backpacking RF burns. Kraus calls such a > "vertical 1/2WL sleeve antenna. On edge it looks like: > > -------------------+ > -------------------------------+ 1/4WL > ==================================================== > -------------------------------+ > -------------------+ > 1/4WL > -- > 73, Cecil http://www.qsl.net/w5dxp In that case I do that, and feed it all up the inside of the top element of a fishing pole I also use for SOTA work with a small beam. I can then seal it in with aradite. Thanks again Steve Article: 219012 of rec.radio.amateur.antenna From: Bruce in Alaska Subject: Re: 900MHz antenna at sea surface References: <1130962168.655457.263840@f14g2000cwb.googlegroups.com> Message-ID: Date: Thu, 03 Nov 2005 19:03:27 GMT In article <1130962168.655457.263840@f14g2000cwb.googlegroups.com>, "jmorash" wrote: > Hi folks, > > I've got some background in EE, but know very little about antennas > (though I have a copy of the ARRL Antenna Book I'm reading now), so > please bear with me if these are newbie questions. > > I need to communicate with a device floating on the surface of the > ocean, at ranges of several miles or more, using a 900MHz radio link. > Vertically polarized seems to be the way to go, to get true > omnidirectional reception. My shore- or ship-side antenna can easily be > placed 20' or more above the surface of the water, and I can use an > off-the-shelf, moderate gain (5-6 dB) product with a nice fiberglass > radome, etc. > > It's the remote side that's the problem. I need to fabricate my own > antenna, rather than buying one, for packaging and waterproofing > reasons. I have a 50 ohm coax transmission line coming out of the > electronics housing; right now I'm just modifying the end of that cable > into a "coaxial dipole" (design I found on the internet). This is a 1/2 > wave section of core, with the corresponding 1/2 wave section of shield > folded back down over the feedline, to form a simple dipole. > > The coaxial dipole works OK at short ranges (up to a mile or so), but > there must be a better way to do this. In fact, based on the stuff I'm > reading, it seems that a dipole is a "balanced" antenna, but a coax > feed is "unbalanced" ... would I be better off with a whip and small > metal ground plane? How would I match this type of antenna to 50 ohms? > What sort of instrument would I need in order to check the impedance? > Essentially I'm looking for something easy to build without much (if > any) tuning required, doesn't need to be high gain. > > It will be tough to get the antenna more than a foot (maybe two) out of > the water, and the platform will be rolling and bobbing around a lot, > so I'm reluctant to use the seawater as a ground plane. Figure the > tuning would change too much. I also expect that in general, a low-gain > antenna on the remote side will be better - generous vertical > beamwidth. > > thanks for any suggestions > --Jim Morash > You might want to look a a 1/2 Wave vertical base loaded antenna similar to the 1/2 Wave used on sailboat mast tops. Morad makes one for Vhf. Your real problem will be, when weather causes the SeaState to be higher than the antenna above the wave troughs. In this state you range is going to be considerably reduced whenever the bouy is in a trough. You might just look at designing a fiberglass antenna mast like 6 Ft long with a counterweight at the bottom anchorpoint, the electronics package in the middle, and the antenna at the top, which would give the bouy's antenna 3 Ft elevation above the SeaState. In a past life, I designed some monitoring bouys for NOAA, and this is how we solved the antenna problems. Still didn't solve all the SeaState problems for Heavy Seas, but worked very well for up to 4 Ft Seas. 900 Mhz isn't exactly the best choice for Maritime bouys, for just these reasons. You ight also look at the transmission data protocol, and see if it is compatable with lost packet recovery techneques, as when the bouy is in moderate to heavy seas, you going to lose about half the data packets due to SeaState Path losses, which will seriuously cut into the data thruput your expecting. Bruce in alaska -- add a <2> before @ Article: 219013 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: 900MHz antenna at sea surface Date: Thu, 03 Nov 2005 11:30:18 -0800 Message-ID: <11mkpacbse140df@corp.supernews.com> References: <1130962168.655457.263840@f14g2000cwb.googlegroups.com> <1130969434.891524.293360@z14g2000cwz.googlegroups.com> Dave wrote: > > a solid ground plane would be more efficient, but is of course bigger, > heavier, and more wind load if you are worried about it blowing around. the > 3-4 radials bent down gives an easy way to fine tune the impedance... of > course if they aren't stiff enough they can get bent if slapped around in > waves. Why would a solid ground plane be more efficient? What's the loss mechanism in radials? Roy Lewallen, W7EL Article: 219014 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: Antenna gain question Date: Thu, 03 Nov 2005 11:47:21 -0800 Message-ID: References: Richard Clark wrote: > On Fri, 28 Oct 2005 20:37:07 GMT, Ron wrote: > > >>Assume an incoming rf signal has exactly the same strength in all 3 >>dimensions i.e., completely omnidirectional. Question: would an >>antenna having gain capture any more signal power than a completely >>omnidirectional antenna with no gain? > > > Hi All, > > Well, it is time to discard the speculation and let modeling approach > this for an answer that at least offers more than swag. > > First we strip away the sphere and solve this in two dimensions. To > do that we simply construct a ring of sources surrounding the > prospective antennas and let the winning design emerge. > > EZNEC+ ver. 4.0 > > Dipole in Ring of Sources 11/2/2005 10:00:48 PM > > --------------- LOAD DATA --------------- > > Frequency = 70 MHz > > Load 1 Voltage = 4.783 V. at 23.52 deg. > Current = 0.06643 A. at 23.52 deg. > Impedance = 72 + J 0 ohms > Power = 0.3177 watts > > Total applied power = 2000 watts > > Total load power = 0.3177 watts > Total load loss = 0.001 dB > > > EZNEC+ ver. 4.0 > > Vert Yagi in Ring of Sources 11/2/2005 10:21:32 PM > > --------------- LOAD DATA --------------- > > Frequency = 70 MHz > > Load 1 Voltage = 1.418 V. at 25.9 deg. > Current = 0.1182 A. at 25.9 deg. > Impedance = 12 + J 0 ohms > Power = 0.1676 watts > > Total applied power = 2000 watts > > Total load power = 0.1676 watts > Total load loss = 0.0 dB > > > As the Bard would offer, there's many a slip between the cup and the > lip. For a first pass approximation, and for all the potential for > errors (which can now be routed out instead of gummed to death), it > appears that the low gain (directivity) dipole absorbs more power than > the high gain (directivity) yagi. > > 73's > Richard Clark, KB7QHC Hi Richard, What is the plane of polarization of the ring of sources, and what is the orientation of the dipole? 73, ac6xg Article: 219015 of rec.radio.amateur.antenna From: "Steve Nosko" Subject: Re: What is low profile antenna? Date: Thu, 3 Nov 2005 14:15:24 -0600 Message-ID: References: <1130962926.892429.129340@z14g2000cwz.googlegroups.com> <9acim1t0tlrkajfb4eo9mlecb6tnth1obe@4ax.com> This is not a technical term. It is a relative descriptor and can mean many things. The words simply mean an antenna that is lower than somebody's idea of a non low-profile or normal antenna. The meaning of "low" should be obvious; "less than... in some respect. Usually a physical dimension." Profile can refer to height or width. Most commonly the height off a surface. Examples already given accepted. 73, Steve, K9DCI "Owen Duffy" wrote in message news:9acim1t0tlrkajfb4eo9mlecb6tnth1obe@4ax.com... > On Wed, 2 Nov 2005 21:09:15 -0000, "Dave" wrote: > > > > >"shuisheng" wrote in message > >news:1130962926.892429.129340@z14g2000cwz.googlegroups.com... > >>I am new to antenna field. Anyboday can explain to me what is low > >> profile antenna? Many thanks. > >> > > > >in addition to the other definitions of 'low profile' it could also refer to > > Some of those "other definitions" might be better described "low > (visual) impact", rather than low profile. > > >a thin aerodynamic antenna such as the patch antennas and other designs used > >for car roofs for satellite reception or on aircraft where air flow is > >critical. > > Sounds good. > > > Owen > -- Article: 219016 of rec.radio.amateur.antenna From: "Steve Nosko" Subject: Re: 900MHz antenna at sea surface Date: Thu, 3 Nov 2005 14:39:55 -0600 Message-ID: References: <1130962168.655457.263840@f14g2000cwb.googlegroups.com> <10021-436A3544-176@storefull-3251.bay.webtv.net> <1131039043.785167.82020@g44g2000cwa.googlegroups.com> Finally someone mentinoed the curvature of the sea... Answers: The 1/4 wave ground plane with a flat plate or 3-5 radials [drooping or not]; the coaxial "sleeve" dipole and the "J" are all pretty much the same thing / pattern-wise. The "J" and sleeve/coaxial dipole may be easier to get up higher, however. The sleeve dipole is a 1/2 wave TOTAL, just like a regular dipole and coax feed is standard. The "j" is nothing more than an end fed 1/2 wave (where the 1/2 wave dipole is a center fed half-wave). These are all fairly simple to make and the "J" shouldn't be a big problem, even with it's much debated so-called feed-line radiation 'problem'. They work just fine. I think the main issues are: 1- As Richard correctly points out, sea / earth curvature means there is a minimum altitude required for a given receiver distance. With this case of the low "bouy", it will be the larger of determining factors and the other end will require greater altitude to make up for small changes at the "bouy". 2- Sea action means an omni gain antenna is contraindicated (not a good idea) because there will be larger variations in signal strength as it bobs around. This is because this "gain" is obtained by compressing the radiation pattern more toward the horizontal and as the "bouy" rocks, you more quickly get to the points where the signal drops off - above and below the horizontal where the signal peaks. Trying to get a "stable" platform with non active means (perhaps a weighted pendulub under the antenna on a gimble) won't work well due to the accelelrations involved - it may rock more than the "bouy". I would first try a stabilizing "keel" if this is an option, to provide a little stability to the "bouy". Depending on its construction, it may rock moerthan the surface, but be stabilized by being "anchored" to the water below (which win't be moving as much as teh "bouy" can. Just like in real estate, the three most inportant things in antennas are altitude, altitude altitude... Hope this helps & good luck 73, Steve, K,9.D;C'I "jmorash" wrote in message news:1131039043.785167.82020@g44g2000cwa.googlegroups.com... > Richard (& Bob), > > I didn't think of simply calculating the distance to the horizon... > oops. > > The problem is that this is a mobile device that will spend most of its > time underwater. It will not be particularly stable at the free > surface, hence it will be tough to support a tall antenna mast without > it waving around wildly. The taller it is, the more it's going to move > around. > Article: 219017 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: Antenna gain question Date: Thu, 03 Nov 2005 13:44:47 -0800 Message-ID: References: <45skm1h8c5ah4ooa1ll3eotts2gu7o3k0u@4ax.com> Richard Clark wrote: > On Thu, 03 Nov 2005 11:47:21 -0800, Jim Kelley > wrote: > > >>What is the plane of polarization of the ring of sources, and what is >>the orientation of the dipole? > > > Hi Jim, > > Vertical in free space (which, of course, has no direction, but we > know what Vertical implies). This also includes the yagi. If you wouldn't mind, try moving your Yagi a half wave forward or reverse. ac6xg Article: 219018 of rec.radio.amateur.antenna From: N7ZZT - Eric Oyen Subject: Re: Looking for a male-any race is fine References: <5h9km1h2ud7v4hro4nsdmio0j2ft77rnhl@4ax.com> Message-ID: Date: Thu, 03 Nov 2005 16:01:24 -0700 N7ZZT - Eric Oyen wrote: > Hello, > I am a swm, 31 years old and blind. I am seeking a > male to be my > partner. Race is not a particular point here. he > must be > understanding and intelligent. > > > Interests are hikingm camping, radio, sci-fi and > cooking. > > > Since I am relatively new at this (not much > experience), I am willing > to learn. My social skills are not well honed, so > I may be a little > rough around the edges. > > > > _________________________________________ > Usenet Zone Free Binaries Usenet Server > More than 140,000 groups > Unlimited download > http://www.usenetzone.com to open account hehehehe. trying to forge me and using an old forge at that? HAHAHAHA try again! -- DE N7ZZT Eric Oyen Phoenix, Arizona e-mail: n7zzt(at)hotmail(dot)com the difference between intelligence and stupidity is that intelligence has its limits. Article: 219019 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: Antenna gain question Date: Thu, 03 Nov 2005 15:13:53 -0800 Message-ID: References: <45skm1h8c5ah4ooa1ll3eotts2gu7o3k0u@4ax.com> <694lm11uggfh0vhmk4t3c5i39p8tr44sgg@4ax.com> Richard Clark wrote: > On Thu, 03 Nov 2005 13:44:47 -0800, Jim Kelley > wrote: > > >>If you wouldn't mind, try moving your Yagi a half wave forward or reverse. > > > Moving back one half wave: > > EZNEC+ ver. 4.0 > > Vert Yagi in Ring of Sources 11/3/2005 2:37:02 PM > > --------------- LOAD DATA --------------- > > Frequency = 70 MHz > > Load 1 Voltage = 1.655 V. at -135.94 deg. > Current = 0.1379 A. at -135.94 deg. > Impedance = 12 + J 0 ohms > Power = 0.2283 watts > > Total applied power = 2000 watts > > Total load power = 0.2283 watts > Total load loss = 0.0 dB > > > moving it such that its "driven" element is dead center to all > radiators (original configuration had the reflector in dead center): > > EZNEC+ ver. 4.0 > > Vert Yagi in Ring of Sources 11/3/2005 2:40:58 PM > > --------------- LOAD DATA --------------- > > Frequency = 70 MHz > > Load 1 Voltage = 1.584 V. at -22.13 deg. > Current = 0.132 A. at -22.13 deg. > Impedance = 12 + J 0 ohms > Power = 0.2091 watts > > Total applied power = 2000 watts > > Total load power = 0.2091 watts > Total load loss = 0.0 dB > > 73's > Richard Clark, KB7QHC It looks like you'd have to use an array of non-coherent sources in order to get rid of the phase cancellation effects (and really see what's going on). Thanks Richard. ac6xg Article: 219020 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: Antenna gain question Date: Thu, 03 Nov 2005 17:42:58 -0800 Message-ID: References: <45skm1h8c5ah4ooa1ll3eotts2gu7o3k0u@4ax.com> <694lm11uggfh0vhmk4t3c5i39p8tr44sgg@4ax.com> Richard Clark wrote: > On Thu, 03 Nov 2005 15:13:53 -0800, Jim Kelley > wrote: > > >>It looks like you'd have to use an array of non-coherent sources in >>order to get rid of the phase cancellation effects (and really see >>what's going on). > > > Hi Jim, > > Then it would be answering a different problem. > > 73's > Richard Clark, KB7QHC An antenna one, rather than an antenna +/- source one. Yes. 73, ac6xg Article: 219021 of rec.radio.amateur.antenna From: "Mike Kulyk" Subject: Swap. NEW ARRL ANTENNA BOOK 20ed. Message-ID: Date: Fri, 4 Nov 2005 07:51:47 -0500 This is a new ARRL Antenna Book , cd and all.. never opened. FOR ARRL Handbook.. New or one -2 years old.. Hardcover preferred.. Mike WB2GLW Article: 219022 of rec.radio.amateur.antenna From: "T.E.O" Subject: Antenna - Page 25-27 - Sept. 83' QST Message-ID: Date: Fri, 04 Nov 2005 14:35:58 GMT I'm trying to get some info on the Antenna on Pages 25-27 of Sept. 83' QST. I don't have access to the article & I'm wondering what the dimensions of the antenna are, the feed point/method & the ground plane (if any). Any help would be appreciated. Article: 219023 of rec.radio.amateur.antenna From: "Rod Maupin" Subject: Selecting a rotator Date: Fri, 4 Nov 2005 09:25:11 -0800 Message-ID: <11mn6bmit0a6e2d@corp.supernews.com> I have never purchased a rotator before and I have one question. You look at the specs for a given rotator, and it says that it will handle say up to 10 square feet wind load area. You then look at the antenna specs, and if the Wind Surface Area for it is less than 10 square feet, then you have a match? Is this correct? Thanks for the help. Rod KI7CQ Article: 219024 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: Antenna gain question Date: Fri, 04 Nov 2005 09:44:42 -0800 Message-ID: References: <45skm1h8c5ah4ooa1ll3eotts2gu7o3k0u@4ax.com> <694lm11uggfh0vhmk4t3c5i39p8tr44sgg@4ax.com> <4velm1dd5lp7trcuncsf2e5c8ctlhjgavt@4ax.com> Very nice work. Dissapointingly ambiguous results. Thank you. ac6xg Richard Clark wrote: > On Thu, 03 Nov 2005 15:13:53 -0800, Jim Kelley > wrote: > >>use an array of non-coherent sources > > > EZNEC+ ver. 4.0 > > Dipole in Ring of Rnd Sources 11/3/2005 5:39:03 PM > > --------------- LOAD DATA --------------- > > Frequency = 70 MHz > > Load 1 Voltage = 0.002611 V. at -33.23 deg. > Current = 3.627E-05 A. at -33.23 deg. > Impedance = 72 + J 0 ohms > Power = 9.47E-08 watts > > Total applied power = 1364 watts > > Total load power = 9.47E-08 watts > Total load loss = 0.0 dB > > then moved quarterwave: > > EZNEC+ ver. 4.0 > > Dipole in Ring of Rnd Sources 11/3/2005 5:41:17 PM > > --------------- LOAD DATA --------------- > > Frequency = 70 MHz > > Load 1 Voltage = 0.00676 V. at -110.1 deg. > Current = 9.389E-05 A. at -110.1 deg. > Impedance = 72 + J 0 ohms > Power = 6.348E-07 watts > > Total applied power = 1364 watts > > Total load power = 6.348E-07 watts > Total load loss = 0.0 dB > > then moved backwards a quarterwave > > EZNEC+ ver. 4.0 > > Dipole in Ring of Rnd Sources 11/3/2005 5:44:52 PM > > --------------- LOAD DATA --------------- > > Frequency = 70 MHz > > Load 1 Voltage = 0.004604 V. at 29.97 deg. > Current = 6.395E-05 A. at 29.97 deg. > Impedance = 72 + J 0 ohms > Power = 2.944E-07 watts > > Total applied power = 1364 watts > > Total load power = 2.944E-07 watts > Total load loss = 0.0 dB > > EZNEC+ ver. 4.0 > > Yagi in Ring of Rnd Sources 11/3/2005 5:48:14 PM > > --------------- LOAD DATA --------------- > > Frequency = 70 MHz > > Load 1 Voltage = 0.07004 V. at 66.62 deg. > Current = 0.005837 A. at 66.62 deg. > Impedance = 12 + J 0 ohms > Power = 0.0004088 watts > > Total applied power = 1364 watts > > Total load power = 0.0004088 watts > Total load loss = 0.0 dB > > moved back halfwave: > > EZNEC+ ver. 4.0 > > Yagi in Ring of Rnd Sources 11/3/2005 5:51:43 PM > > --------------- LOAD DATA --------------- > > Frequency = 70 MHz > > Load 1 Voltage = 0.09133 V. at -53.63 deg. > Current = 0.007611 A. at -53.63 deg. > Impedance = 12 + J 0 ohms > Power = 0.0006952 watts > > Total applied power = 1364 watts > > Total load power = 0.0006952 watts > Total load loss = 0.0 dB > > >>(and really see what's going on) > > > Hmmm, at least 1000 times more response... so what's going on? (aside > from a possibly poor implementation of random). Trying to refine the > sources table with tighter random assignments is positively brutal > under EZNEC's primitive (read no) handling of columnar data. > > 73's > Richard Clark, KB7QHC Article: 219025 of rec.radio.amateur.antenna From: "David G. Nagel" Subject: Re: Antenna - Page 25-27 - Sept. 83' QST Date: Fri, 04 Nov 2005 11:55:55 -0600 Message-ID: <11mn85hl4a8172c@corp.supernews.com> References: T.E.O wrote: > I'm trying to get some info on the Antenna on Pages 25-27 of Sept. 83' QST. > > I don't have access to the article & I'm wondering what the dimensions of > the antenna are, the feed point/method & the ground plane (if any). > > Any help would be appreciated. > > > A keyword search of the ARRL files turns up a reference but does not have a link to the article. You might try getting the CD for 1983. The article will be on it. Dave WD9BDZ Article: 219026 of rec.radio.amateur.antenna From: "Ralph Mowery" References: <11mn6bmit0a6e2d@corp.supernews.com> Subject: Re: Selecting a rotator Message-ID: Date: Fri, 04 Nov 2005 17:56:44 GMT "Rod Maupin" wrote in message news:11mn6bmit0a6e2d@corp.supernews.com... > I have never purchased a rotator before and I have one question. > > You look at the specs for a given rotator, and it says that it will handle > say up to 10 square feet wind load area. You then look at the antenna > specs, and if the Wind Surface Area for it is less than 10 square feet, then > you have a match? Is this correct? > > Thanks for the help. > > Rod KI7CQ That is mostly correct. The rotator sqft rateing is the maximum of the rotator. The antenna will also have a specification of the sqft rateing. If you have two or more antennas on teh rotator then you have to add the sqft of each antenna and come up with less than the rotator rating. The bigger the differance, the more safety factor you have. It is not usually a problem but also check for the weight the rotator will support. Also if the rotator is inside the tower it will handle a bigger load than if it is mounted to a pipe on top of the tower. Article: 219027 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: Antenna gain question Date: Fri, 04 Nov 2005 10:32:07 -0800 Message-ID: References: <45skm1h8c5ah4ooa1ll3eotts2gu7o3k0u@4ax.com> <694lm11uggfh0vhmk4t3c5i39p8tr44sgg@4ax.com> <4velm1dd5lp7trcuncsf2e5c8ctlhjgavt@4ax.com> Richard, It's not clear what aspect of your sources is "Rnd", but the fact that they are monochromatic is still problematic. 73, ac6xg Jim Kelley wrote: > Very nice work. Dissapointingly ambiguous results. > > Thank you. > > ac6xg > > Richard Clark wrote: > >> On Thu, 03 Nov 2005 15:13:53 -0800, Jim Kelley >> wrote: >> >>> use an array of non-coherent sources >> >> >> >> EZNEC+ ver. 4.0 >> >> Dipole in Ring of Rnd Sources 11/3/2005 5:39:03 PM >> >> --------------- LOAD DATA --------------- >> >> Frequency = 70 MHz >> >> Load 1 Voltage = 0.002611 V. at -33.23 deg. >> Current = 3.627E-05 A. at -33.23 deg. >> Impedance = 72 + J 0 ohms >> Power = 9.47E-08 watts >> >> Total applied power = 1364 watts >> >> Total load power = 9.47E-08 watts >> Total load loss = 0.0 dB >> >> then moved quarterwave: >> >> EZNEC+ ver. 4.0 >> >> Dipole in Ring of Rnd Sources 11/3/2005 5:41:17 PM >> >> --------------- LOAD DATA --------------- >> >> Frequency = 70 MHz >> >> Load 1 Voltage = 0.00676 V. at -110.1 deg. >> Current = 9.389E-05 A. at -110.1 deg. >> Impedance = 72 + J 0 ohms >> Power = 6.348E-07 watts >> >> Total applied power = 1364 watts >> >> Total load power = 6.348E-07 watts >> Total load loss = 0.0 dB >> >> then moved backwards a quarterwave >> >> EZNEC+ ver. 4.0 >> >> Dipole in Ring of Rnd Sources 11/3/2005 5:44:52 PM >> >> --------------- LOAD DATA --------------- >> >> Frequency = 70 MHz >> >> Load 1 Voltage = 0.004604 V. at 29.97 deg. >> Current = 6.395E-05 A. at 29.97 deg. >> Impedance = 72 + J 0 ohms >> Power = 2.944E-07 watts >> >> Total applied power = 1364 watts >> >> Total load power = 2.944E-07 watts >> Total load loss = 0.0 dB >> >> EZNEC+ ver. 4.0 >> >> Yagi in Ring of Rnd Sources 11/3/2005 5:48:14 PM >> >> --------------- LOAD DATA --------------- >> >> Frequency = 70 MHz >> >> Load 1 Voltage = 0.07004 V. at 66.62 deg. >> Current = 0.005837 A. at 66.62 deg. >> Impedance = 12 + J 0 ohms >> Power = 0.0004088 watts >> >> Total applied power = 1364 watts >> >> Total load power = 0.0004088 watts >> Total load loss = 0.0 dB >> >> moved back halfwave: >> >> EZNEC+ ver. 4.0 >> >> Yagi in Ring of Rnd Sources 11/3/2005 5:51:43 PM >> >> --------------- LOAD DATA --------------- >> >> Frequency = 70 MHz >> >> Load 1 Voltage = 0.09133 V. at -53.63 deg. >> Current = 0.007611 A. at -53.63 deg. >> Impedance = 12 + J 0 ohms >> Power = 0.0006952 watts >> >> Total applied power = 1364 watts >> >> Total load power = 0.0006952 watts >> Total load loss = 0.0 dB >> >> >>> (and really see what's going on) >> >> >> >> Hmmm, at least 1000 times more response... so what's going on? (aside >> from a possibly poor implementation of random). Trying to refine the >> sources table with tighter random assignments is positively brutal >> under EZNEC's primitive (read no) handling of columnar data. >> >> 73's >> Richard Clark, KB7QHC > > Article: 219028 of rec.radio.amateur.antenna From: John Ferrell Subject: MFJ-269 Antenna/SWR/RF Analyzer Message-ID: Date: Fri, 04 Nov 2005 19:43:07 GMT I am considering ordering the MFJ-269 HF/VHF/UHF Antenna/SWR/RF Analyzer. It sounds like a Swiss Army knife device and I should be able to send a lot of old equipment to Ebay. Does anyone have any comments to make on it? Good or bad? I have read the review in May 2005 QST and the manual available at their website. John Ferrell, W8CCW Article: 219029 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: Antenna gain question Date: Fri, 04 Nov 2005 11:42:43 -0800 Message-ID: References: <45skm1h8c5ah4ooa1ll3eotts2gu7o3k0u@4ax.com> <694lm11uggfh0vhmk4t3c5i39p8tr44sgg@4ax.com> <4velm1dd5lp7trcuncsf2e5c8ctlhjgavt@4ax.com> Richard Clark wrote: > Anyway, I would surmise that if I could achieve both random phase and > frequency distribution, then the difference between a simple dipole's > response and that of a yagi antenna would be trivial. Trivial would be a nice change. > This would be a > given seeing that the parasitic elements would be virtually invisible, > rendering the "driven" element un-differentiable from the simple > dipole. i.e. what Roy said. But I think there's still more to it. I tried to give the other Richard a hint about it but it didn't resonate. 73, ac6xg Article: 219030 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: MFJ-269 Antenna/SWR/RF Analyzer Date: Fri, 04 Nov 2005 12:13:06 -0800 Message-ID: <11mng6ldmmb08ed@corp.supernews.com> References: "Swiss Army knife" is a good metaphor. In your pocket, it's always available and handy for that simple job. It's got a saw good for fast, rough cutting, but no competition for a chain saw for speed or a scroll saw for precision. The file will cut metal, but it's not a Swiss file set or a wood rasp either. And so forth. Likewise the MFJ. I use is frequently for a quick measurement, and that's often good enough. But when I really need precision, out comes the GR bridge, network analyzer, and whatever other real tools are required. Ironically, the thing it does worst, in an urban setting at least, is actually measure antenna impedance. Like any broadband impedance meter, it's dismally bad at that particular job because RF from broadcast and other sources drives it bonkers. So by all means get one. You'll find you use it a lot. But don't be too quick to unload your other gear. Roy Lewallen, W7EL John Ferrell wrote: > I am considering ordering the MFJ-269 HF/VHF/UHF Antenna/SWR/RF > Analyzer. > > It sounds like a Swiss Army knife device and I should be able to send > a lot of old equipment to Ebay. Does anyone have any comments to make > on it? Good or bad? > > I have read the review in May 2005 QST and the manual available at > their website. > > John Ferrell, W8CCW Article: 219031 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Antenna gain question References: <45skm1h8c5ah4ooa1ll3eotts2gu7o3k0u@4ax.com> <694lm11uggfh0vhmk4t3c5i39p8tr44sgg@4ax.com> <4velm1dd5lp7trcuncsf2e5c8ctlhjgavt@4ax.com> Message-ID: Date: Fri, 04 Nov 2005 20:29:45 GMT Jim Kelley wrote: > i.e. what Roy said. But I think there's still more to it. I tried to > give the other Richard a hint about it but it didn't resonate. Then obviously your XC didn't equal your XL. -- 73, Cecil http://www.qsl.net/w5dxp Article: 219032 of rec.radio.amateur.antenna From: "Steve Nosko" Subject: Re: 900MHz antenna at sea surface Date: Fri, 4 Nov 2005 13:49:52 -0600 Message-ID: References: <1130962168.655457.263840@f14g2000cwb.googlegroups.com> <10021-436A3544-176@storefull-3251.bay.webtv.net> <1131039043.785167.82020@g44g2000cwa.googlegroups.com> <1131057506.111016.316920@g14g2000cwa.googlegroups.com> "jmorash" wrote in message news:1131057506.111016.316920@g14g2000cwa.googlegroups.com... > Steve, > > I agree that the sleeve dipole, coax-based J, and whip with radials > should all have the same radiation pattern, but I get the impression > that performance might vary quite a bit (specifically the impedance > matching?). Nope. I disagree. Commercial sleeve-coaxial dipoles are driven w 50 ohm coax, I have one - works great to extend the range of my 5-W 2 Meter hand leld for various temporary Ham communication assisted events. If you are worried about the so called 50 sv 75 ohm mis match.. Believe me, it is nothing. Ditto for the gnd plane 37 ohm mismatch (identical SWR non issue). The antenna length can even be adjusted to get an improvesd SWR and this may not be where the antenna is purely resistive. This is way, way down the list of worries for your situation. "J" s are matched to 50 ohms. I don't believe the much discussed feed-line radiation is a significant practical problem. Something I thought of after clicking last time. Look @ the Arrow antenna version of the "J". It is also much discussed and argued about, but works. I haven't studied it enough to have a well reasoned opinion, but highly suspect it has advantages over the standard "J" that are not only mechanical. He has no 900 MHz version, but it is a rugged construction idea. I want to get one and measure the "bad" external feed line currents (yes, I have Fischer clamp-on RF current probes) http://www.arrowantennas.com There's also the "sleeve dipole with the cut shield" referred to previously on this group which looks easy and interesting. . http://www.ansoft.com/news/articles/04.05_MWJ.pdf One more thing I just thought of to worry about. Salt spray: 1- Corrosion of the materials used. 2- Geting into critical locations and causing unwanted conduction. I think you mentined a radome, which reminds me... 3- A plastic radome (Pipe or whatever) will require you to SHORTEN the radiating elements a bit or you'll resonate too low in frequency. [[ build, insert THEN measure]] 73, Steve, K,9.D;C'I > > As far as increasing height goes, I agree, the thinner antennas will be > easier to raise than the version with radials. > > Thanks all for helping me think this through. Now I need to do some > testing. > Article: 219033 of rec.radio.amateur.antenna From: Roger Subject: Re: Question on shooting a line Message-ID: References: <1130633563.967446.51040@g49g2000cwa.googlegroups.com> <313030303837383543660A4434@zetnet.co.uk> Date: Fri, 04 Nov 2005 16:31:10 -0500 On Tue, 01 Nov 2005 01:13:09 GMT, Ed wrote: > > >> Why not just use the rod and reel? Admittedly some can throw farther >> than they can cast. > > > I doubt there are very many people who can either throw, or cast a >line, at 70 feet, over a particular branch of a rather densely packed >conifer tree. I can do it, however, with a slingshot. A bow or crossbow >would be even better, I'll admit. > Well, back in my college days (the first time) I had a phys ed class called "The techniques of Bait and Fly Casting". We had to be able to put the "bait" through a 16" tire from the width of the field house (a bit wider than the width of a basketball court.) to pass. I haven't used a spinning rod in over 25 years. I'd be lucky to hit the other side of the field house let alone the hole in the tire. <:-)) Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com > > Ed Article: 219034 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: Antenna gain question Date: Fri, 04 Nov 2005 13:53:42 -0800 Message-ID: References: <45skm1h8c5ah4ooa1ll3eotts2gu7o3k0u@4ax.com> <694lm11uggfh0vhmk4t3c5i39p8tr44sgg@4ax.com> <4velm1dd5lp7trcuncsf2e5c8ctlhjgavt@4ax.com> Cecil Moore wrote: > Jim Kelley wrote: > >> i.e. what Roy said. But I think there's still more to it. I tried to >> give the other Richard a hint about it but it didn't resonate. > > > Then obviously your XC didn't equal your XL. Probably just a difference in wavelength. ac6xg Article: 219035 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: Antenna gain question Date: Fri, 04 Nov 2005 15:39:18 -0800 Message-ID: References: <45skm1h8c5ah4ooa1ll3eotts2gu7o3k0u@4ax.com> <694lm11uggfh0vhmk4t3c5i39p8tr44sgg@4ax.com> <4velm1dd5lp7trcuncsf2e5c8ctlhjgavt@4ax.com> Richard Clark wrote: > On Fri, 04 Nov 2005 11:42:43 -0800, Jim Kelley > wrote: > >>>This would be a >>>given seeing that the parasitic elements would be virtually invisible, >>>rendering the "driven" element un-differentiable from the simple >>>dipole. >> >>i.e. what Roy said. > > >>On Wed, 02 Nov 2005 00:11:09 -0800, Roy Lewallen among many things wrote: >> >> >>>I have to admit, I was looking at this a[s] more of a problem of equal >>>signals arriving from all directions > > > Hi Jim, > > I also approached the problem the same way, this is in glaring > contrast to what I've written in the past two posts which are vastly > divergent from this sense of "equal signals." > > As I originally presented data from the model of "equal signals > arriving from all directions" it presented that a dipole's response > was separable from that of a yagi, and showed more response which > contradicts some correspondents, and aligns with others. > > Such an outcome stands to reason, the yagi cannot see all sources, the > dipole can. If I illuminated the yagi from each source in turn (all > others off) and correlated the response to the source's angle, the > composite would simply reveal the characteristic yagi response lobe > and the sum of those powers MUST fall below the total power available > to the dipole. > > The one over-riding difference between all these scenarios and the > expectations of the yagi is that the yagi is not illuminated with a > plane field, but with a radial field. The composite front of many > sources presents a complex antenna (the yagi) with the appearance of a > wave of extremely high curvature impinging upon it. The mechanics of > gain/directivity are not going to function in the same manner to that > yagi for both fashions of applying the power. Hence the yagi fails to > exhibit a higher response than the simple dipole. > > 73's > Richard Clark, KB7QHC Let me thank you again for the work you've put in on this. The thing is, the idea of squeezing a dipole field pattern into the shape of a Yagi pattern for example, pretty much dictates that with the proper field geometry, we should be able to realize equal amounts of energy in both antennas. I think that's the correct answer. I'm just trying to see a way to get to it. Another approach might be to integrate the results from a large number of point sources. 73, AC6XG Article: 219036 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: 900MHz antenna at sea surface Date: Fri, 04 Nov 2005 15:42:17 -0800 Message-ID: <11mnserb5miuj86@corp.supernews.com> References: <1130962168.655457.263840@f14g2000cwb.googlegroups.com> <10021-436A3544-176@storefull-3251.bay.webtv.net> <1131039043.785167.82020@g44g2000cwa.googlegroups.com> <1131057506.111016.316920@g14g2000cwa.googlegroups.com> jmorash wrote: > > I agree that the sleeve dipole, coax-based J, and whip with radials > should all have the same radiation pattern, but I get the impression > that performance might vary quite a bit (specifically the impedance > matching?). Impedance matching isn't much of a problem with any of those antennas. The main issue is feedline decoupling. Current will end up on the outside of the feedline unless, of course, your antenna is mounted directly on a metal structure -- in which case the current will end up on the outside of the metal structure. This current radiates just like the current in the antenna, and this added radiation can cause a number of problems. One is that it can modify the pattern and reduce the radiation toward the horizon. Another is that the current can get back into the transmitter and other circuitry where it doesn't belong. Finally, it can effect a change in feedpoint impedance, since the coax is part of the antenna you probably didn't account for. The current can originate by two mechanisms, conducted and coupled. http://eznec.com/Amateur/Articles/Baluns.pdf explains the conducted mechanism. Current can be coupled from the antenna to the feedline even if you're using a solid ground plane of moderate diameter, and all the popular implementations have coupled current to some extent. If you search for a while, you'll find people both raving about and raving at J-Poles. I suspect this is at least partially due to the amount and phase of coupled current they ended up with due to their particular installation. The amount of coupled current depends on the length and path of the feedline, as well as the path to ground or some large body. If I were designing the antenna you describe, I'd use a "current balun" (common mode choke -- see the balun article) at the feedpoint and about a quarter wavelength down the line. At that frequency, a good size ferrite core or two of the right type might provide adequate impedance. Half wave antennas have relatively little conducted current because the feedpoint impedance is so high. But feedline current can still exist due to coupling. Roy Lewallen, W7EL Article: 219037 of rec.radio.amateur.antenna From: John Ferrell Subject: Re: MFJ-269 Antenna/SWR/RF Analyzer Message-ID: <86snm1d2aob4sm5rmlqc5s0ehdpt1a2349@4ax.com> References: <11mng6ldmmb08ed@corp.supernews.com> Date: Fri, 04 Nov 2005 23:42:16 GMT Thanks for the quick reply. The "old equipment" I am referring to is pretty primitive and quite old. The only really good pice of equipment I wonder about replacing is an Heathkit IM-4190 directional coupler for 100-1000 mhz. It was not available for long and it has served me well on 144 & 440 mhz. John Ferrell, W8CCW On Fri, 04 Nov 2005 12:13:06 -0800, Roy Lewallen wrote: >"Swiss Army knife" is a good metaphor. In your pocket, it's always >available and handy for that simple job. It's got a saw good for fast, >rough cutting, but no competition for a chain saw for speed or a scroll >saw for precision. The file will cut metal, but it's not a Swiss file >set or a wood rasp either. And so forth. Likewise the MFJ. I use is >frequently for a quick measurement, and that's often good enough. But >when I really need precision, out comes the GR bridge, network analyzer, >and whatever other real tools are required. > >Ironically, the thing it does worst, in an urban setting at least, is >actually measure antenna impedance. Like any broadband impedance meter, >it's dismally bad at that particular job because RF from broadcast and >other sources drives it bonkers. > >So by all means get one. You'll find you use it a lot. But don't be too >quick to unload your other gear. > >Roy Lewallen, W7EL Article: 219038 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Antenna gain question Date: Fri, 04 Nov 2005 15:45:39 -0800 Message-ID: <11mnsl5ek4mej18@corp.supernews.com> References: <45skm1h8c5ah4ooa1ll3eotts2gu7o3k0u@4ax.com> <694lm11uggfh0vhmk4t3c5i39p8tr44sgg@4ax.com> <4velm1dd5lp7trcuncsf2e5c8ctlhjgavt@4ax.com> Richard Clark wrote: > . . . > Such an outcome stands to reason, the yagi cannot see all sources, the > dipole can. If I illuminated the yagi from each source in turn (all > others off) and correlated the response to the source's angle, the > composite would simply reveal the characteristic yagi response lobe > and the sum of those powers MUST fall below the total power available > to the dipole. > Yet if you provide the same power to the dipole and the Yagi and integrate the total field from each, the total field powers from both are the same. So is reciprocity invalid? Roy Lewallen, W7EL Article: 219039 of rec.radio.amateur.antenna From: "Steve Nosko" Subject: Re: MFJ-269 Antenna/SWR/RF Analyzer Date: Fri, 4 Nov 2005 17:19:37 -0600 Message-ID: References: <11mng6ldmmb08ed@corp.supernews.com> It's ok, but has one known short coming (other than its known and accepted general low/ medium accuracy). It appears to do worse at LOW freqs that the 259. Mine shows about 25% X for a purely resistive 4:1 load (either 200 or 12.5) in the 1-4 Mhz range. A post here not to long ago reported that the QST review showed the same thing. you can't expect lab accuracy for $300... 73, K9DCI "Roy Lewallen" wrote in message news:11mng6ldmmb08ed@corp.supernews.com... > "Swiss Army knife" is a good metaphor. In your pocket, it's always > available and handy for that simple job. It's got a saw good for fast, > rough cutting, but no competition for a chain saw for speed or a scroll > saw for precision. The file will cut metal, but it's not a Swiss file > set or a wood rasp either. And so forth. Likewise the MFJ. I use is > frequently for a quick measurement, and that's often good enough. But > when I really need precision, out comes the GR bridge, network analyzer, > and whatever other real tools are required. > > Ironically, the thing it does worst, in an urban setting at least, is > actually measure antenna impedance. Like any broadband impedance meter, > it's dismally bad at that particular job because RF from broadcast and > other sources drives it bonkers. > > So by all means get one. You'll find you use it a lot. But don't be too > quick to unload your other gear. > > Roy Lewallen, W7EL > > John Ferrell wrote: > > I am considering ordering the MFJ-269 HF/VHF/UHF Antenna/SWR/RF > > Analyzer. > > > > It sounds like a Swiss Army knife device and I should be able to send > > a lot of old equipment to Ebay. Does anyone have any comments to make > > on it? Good or bad? > > > > I have read the review in May 2005 QST and the manual available at > > their website. > > > > John Ferrell, W8CCW Article: 219041 of rec.radio.amateur.antenna From: "T.E.O" References: Subject: Re: Antenna - Page 25-27 - Sept. 83' QST Message-ID: Date: Sat, 05 Nov 2005 01:10:59 GMT I got it. Thanks Fred. Much appreciated. "FredSmith" wrote in message news:c2hnm1lhbuasb8trqiu2239c9c94a0crle@4ax.com... > I just emailed you a copy of the article. > 73 > > On Fri, 04 Nov 2005 14:35:58 GMT, "T.E.O" > wrote: > > > I'm trying to get some info on the Antenna on Pages 25-27 of Sept. 83' QST. > > > >I don't have access to the article & I'm wondering what the dimensions of > >the antenna are, the feed point/method & the ground plane (if any). > > > >Any help would be appreciated. > > > > > Article: 219042 of rec.radio.amateur.antenna From: "Dave Pitzer" Subject: Receiving WWV signal on computer Message-ID: Date: Sat, 05 Nov 2005 02:39:24 GMT Is there a URL where I can hear WWV time signals & announcments? (I realize there is latency that effect the accuracy but this kis unimportant for my purpose.) Thank you, Dave Pitz Article: 219043 of rec.radio.amateur.antenna From: "Hal Rosser" References: <43683106.A6993A2E@shaw.ca> <11mim54bve97rcc@corp.supernews.com> <11mio1h6a2td18f@corp.supernews.com> Subject: Re: How To Put Up An Antenna Message-ID: Date: Fri, 4 Nov 2005 21:45:04 -0500 Oh - of COURSE its a false story - just a good funny one. We all know hams don't use buckets for their tools. It was on some ftp site in the early 90's I think... everyone knew it was just a joke - but you couldn't help but snicker as each paragraph introduced a new wrinkle and a new woe to the unlucky ham. It was written up like it was an explanation to his insurance company. "David G. Nagel" wrote in message news:11mio1h6a2td18f@corp.supernews.com... > Roy Lewallen wrote: > > Hal Rosser wrote: > > > >> That reminds me of a story that used to circulate about the ham writing a > >> letter to the insurance company explaining how he incurred his injuries > >> while working on his antenna tower. > >> Something about: 300 lbs of tools in a bucket at the top of the > >> tower and > >> the bucket was on a rope that went through a pully at the top of the > >> tower. > >> he weighed only 150 lbs > >> and as he accelerated upward, he forgot to turn loose of the rope > >> met the bucket with his head half way up (and again with his ankles > >> half way > >> down because the bottom fell out of the bucket when it hit the ground ). > >> > >> Does anyone have a link to this original story ? > > > > > > The original is almost certainly lost in the mists of time. My dad used > > to tell me a version of that when I was a little kid. And he probably > > heard it from his dad. > > > > Roy Lewallen, W7EL > Mythbusters looked into this myth and ircc they found it not only false > but impossible. I could be wrong though. > > Dave WD9BDZ > > BTW: Glad to see you back Roy... Article: 219044 of rec.radio.amateur.antenna From: "Hal Rosser" References: <43683106.A6993A2E@shaw.ca> <436960EA.93C04432@shaw.ca> <436965C2.CD6E05BC@shaw.ca> Subject: Re: I Found It! Message-ID: Date: Fri, 4 Nov 2005 21:51:10 -0500 I like that version better. Thanks! "Irv Finkleman" wrote in message news:436965C2.CD6E05BC@shaw.ca... > Irv Finkleman wrote: > > > > Hal Rosser wrote: > > > > > > That reminds me of a story that used to circulate about the ham writing a > > > letter to the insurance company > > > > I've got a copy of it somewhere on this machine! I'll see if I can find it! > > Here it is -- it's called sick note! > > ------------------------------------------------------------- > > The Sick Note > > Dear Sir, I write this note to you to tell you of my plight > For at the time of writing I am not a pretty sight > My body is all black and blue, my face a deathly gray > And I write this note to say why I am not at work today > > Whilst working on the 14th floor some bricks I had to clear > To throw them down from such a height was not a good idea > The foreman wasn't very pleased, the bloody awkward sod > And said I'd have to cart them down the ladders in my hod > > Now clearing all those bricks by hand, it was so very slow > So I hoisted up a barrel and secured the rope below > But in my haste to do the job I was to blind to see > That a barrel full of building bricks was heavier than me > > And so when I untied the rope the barrel flew like lead > And clinging tightly to the rope I started up instead > I shot up like a rocket till to my dismay I found > That halfway up I met the bloody barrel coming down > > The barrel broke my shoulder as toward the ground it sped > And when I reached the top I banged the pully with me head > I hung on tightly, numb with shock from this almighty blow > And the barrel spilled out half the bricks, 14 floors below > > Now when those bricks had fallen from the barrel to the floor > I then outweighed the barrel and so started down once more > Still clinging tightly to the rope, my body racked with pain > When halfway down I met the bloody barrel once again > > The force of this collision, halfway up the office block > Caused multiple abrasions and a nasty case of shock > Still clinging tightly to the rope, I fell towards the ground > And I landed on the broken bricks the barrel scattered round > > I lay there groaning on the ground, I thought I'd passed the worst > But the barrel hit the pulleywheel, and then its bottom burst > A shower of bricks rained down on me, I hadn't got a hope > As I lay there bleeding on the ground, I let go the bloody rope > > The barrel was now free to fall and down it came once more > And landed right across me as I lay upon the floor > It broke three ribs and my left arm and I can only say > That I hope you understand why I am not at work today! > > > -- > -------------------------------------- > Diagnosed Type II Diabetes March 5 2001 > Beating it with diet and exercise! > 297/215/210 (to be revised lower) > 58"/43"(!)/44" (already lower too!) > -------------------------------------- > Visit my HomePage at http://members.shaw.ca/finkirv/index.html > Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/index.htm > Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/index.htm > -------------------- > Irv Finkleman, > Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP > Calgary, Alberta, Canada Article: 219045 of rec.radio.amateur.antenna Subject: Re: Receiving WWV signal on computer From: Ed References: Message-ID: Date: Sat, 05 Nov 2005 02:51:58 GMT : > Is there a URL where I can hear WWV time signals & announcments? (I > realize there is latency that effect the accuracy but this kis > unimportant for my purpose.) > WWV is operated by the National Institute of Standards & Technology. http://www.nist.gov/ Time signals are available at: http://nist.time.gov/ Ed K7AAT Article: 219046 of rec.radio.amateur.antenna From: "Dave Pitzer" Subject: AM Commercial radio reception Message-ID: Date: Sat, 05 Nov 2005 02:54:31 GMT Why is it that I can received WCBS @ 880kc fairly well at night but WABC @ 770kc suffers from phase distortion like you wouldn't believe! (I'm about 175 miles from both transmitters.) They are both 50 kwatt stations. And why is it that both WBZ (Boston), WBT (Charlotte, NC), WJR (Detroit) and WBBM (Chicago) come in better than either of the New York City stations? Dave P. Article: 219047 of rec.radio.amateur.antenna From: "Dave Pitzer" References: Subject: Re: Receiving WWV signal on computer Message-ID: Date: Sat, 05 Nov 2005 02:58:53 GMT Ed: Perfect!! Thanks! Dave "Ed" wrote in message news:Xns9704BFFD6EFAFspectrumhogstarbandn@207.106.92.175... > : > > > Is there a URL where I can hear WWV time signals & announcments? (I > > realize there is latency that effect the accuracy but this kis > > unimportant for my purpose.) > > > > WWV is operated by the National Institute of Standards & Technology. > > http://www.nist.gov/ > > Time signals are available at: > > http://nist.time.gov/ > > > Ed K7AAT Article: 219048 of rec.radio.amateur.antenna From: Bob Miller Subject: Re: MFJ-269 Antenna/SWR/RF Analyzer Message-ID: References: Date: Sat, 05 Nov 2005 03:07:58 GMT On Fri, 04 Nov 2005 19:43:07 GMT, John Ferrell wrote: >I am considering ordering the MFJ-269 HF/VHF/UHF Antenna/SWR/RF >Analyzer. > >It sounds like a Swiss Army knife device and I should be able to send >a lot of old equipment to Ebay. Does anyone have any comments to make >on it? Good or bad? > >I have read the review in May 2005 QST and the manual available at >their website. > >John Ferrell, W8CCW My main complaint is if you punch buttons in the wrong sequence to activate its 440 mhz capability, you can blow a diode, or so I've read in the eHam reports. I haven't done it yet, but the it apparently can happen. The capabilities on 440 mhz are quite limited, compared to other frequencies, so you may want to consider the 259, unless you need to measure swr on 440. bob k5qwg Article: 219049 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: AM Commercial radio reception Date: Sat, 5 Nov 2005 03:51:58 +0000 (UTC) Message-ID: References: > Why is it that I can received WCBS @ 880kc fairly well at night but WABC @ > 770kc suffers from phase distortion like you wouldn't believe! (I'm about > 175 miles from both transmitters.) They are both 50 kwatt stations. And why > is it that both WBZ (Boston), WBT (Charlotte, NC), WJR (Detroit) and WBBM > (Chicago) come in better than either of the New York City stations? > > Dave P. ================================ Different frequencies, different directions, different sun angles (even when below the horizon), different ionospheric layer heights, different skip distances, different ground-path terrains and therefore different ground-path loss. ---- Reg. Article: 219050 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: AM Commercial radio reception Date: Sat, 5 Nov 2005 00:11:18 -0600 Message-ID: <6487-436C4D06-493@storefull-3252.bay.webtv.net> References: Dave P. wrote: "Why is it that I can receive WCBS @ 880 kc fairly well at night but WABC @ 770 kc suffers from phase distortion like you wouldn`t believe?" I havn`t looked up the directional patterns of the two stations and don`t know your location. If you should happen to be at the edge of a null in the nighttime directional pattern of WABC, that would likely cause distorted fading. WABC may be clear-channel non-directional day and night for all I know. Not many of these remain in the U.S.A. now. At 175 miles from both transmitters, you suffer interference between the ground wave and sky wave from either transmitter at night, at least occasionally. You probably have solid daytime reception from both stations, but at night, the signal may be stronger, though variable. The sky wave is susceptable to variations in the reflecting layers of the ionosphere at night. These are a function of frequency, reflecting carrier and sidebands differently at times. This can produce overmodulation at times in the received signal. Another factor is likely other stations on the same or adjacent channels which may fade in and out and cause variation from your automatic volume control action even when the interfering stations can not be readily identified. An Adcock, loop, or other directional antenna may produce a big improvement in reception of the desired signal. Finally, WABC is owned by the Walt Disney company. Maybe you should expect Mickey Mouse performance. Best regards, Richard Harrison, KB5WZI Article: 219051 of rec.radio.amateur.antenna From: "Dave Pitzer" References: <6487-436C4D06-493@storefull-3252.bay.webtv.net> Subject: Re: AM Commercial radio reception Message-ID: Date: Sat, 05 Nov 2005 07:40:05 GMT Richard, Both you and Reg have given excellent answers and I thank you both. By the way, you mention directional patterns and nulls. Is there any place I can find polar graphs of commercial broadcast station's antenna patterns? Thanks, Dave P. ==================== "Richard Harrison" wrote in message news:6487-436C4D06-493@storefull-3252.bay.webtv.net... > Dave P. wrote: > "Why is it that I can receive WCBS @ 880 kc fairly well at night but > WABC @ 770 kc suffers from phase distortion like you wouldn`t believe?" > > I havn`t looked up the directional patterns of the two stations and > don`t know your location. If you should happen to be at the edge of a > null in the nighttime directional pattern of WABC, that would likely > cause distorted fading. WABC may be clear-channel non-directional day > and night for all I know. Not many of these remain in the U.S.A. now. > > At 175 miles from both transmitters, you suffer interference between the > ground wave and sky wave from either transmitter at night, at least > occasionally. You probably have solid daytime reception from both > stations, but at night, the signal may be stronger, though variable. The > sky wave is susceptable to variations in the reflecting layers of the > ionosphere at night. These are a function of frequency, reflecting > carrier and sidebands differently at times. This can produce > overmodulation at times in the received signal. Another factor is likely > other stations on the same or adjacent channels which may fade in and > out and cause variation from your automatic volume control action even > when the interfering stations can not be readily identified. An Adcock, > loop, or other directional antenna may produce a big improvement in > reception of the desired signal. > > Finally, WABC is owned by the Walt Disney company. Maybe you should > expect Mickey Mouse performance. > > Best regards, Richard Harrison, KB5WZI > Article: 219052 of rec.radio.amateur.antenna From: ve1jh Subject: Re: AM Commercial radio reception References: <6487-436C4D06-493@storefull-3252.bay.webtv.net> Message-ID: Date: Sat, 05 Nov 2005 09:37:44 GMT There are undoubtedly official sources from the FCC, etc. The best hand-held guide I could recommend would be the National Radio Club's "Night Pattern Book," a fantastic resource for MW DXers and broadcast listeners. Basically it is a book of maps of North America for each domestic broadcast frequency, with dots representing transmitting locations, and the night time radiation pattern around each. It's available from the following link: http://www.nrcdxas.org/catalog/books/ The 5th edition is sold out, but the new 2005-06 edition is scheduled to be out soon. Brent Taylor VE1JH Dave Pitzer wrote: > Richard, > > Both you and Reg have given excellent answers and I thank you both. > > By the way, you mention directional patterns and nulls. Is there any place I > can find polar graphs of commercial broadcast station's antenna patterns? > > Thanks, > > Dave P. Article: 219053 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: AM Commercial radio reception Date: Sat, 5 Nov 2005 11:07:22 +0000 (UTC) Message-ID: References: <6487-436C4D06-493@storefull-3252.bay.webtv.net> > There are undoubtedly official sources from the FCC, etc. > > The best hand-held guide I could recommend would be the National Radio > Club's "Night Pattern Book," a fantastic resource for MW DXers and > broadcast listeners. Basically it is a book of maps of North America > for each domestic broadcast frequency, with dots representing > transmitting locations, and the night time radiation pattern around each. > > It's available from the following link: > > http://www.nrcdxas.org/catalog/books/ > > The 5th edition is sold out, but the new 2005-06 edition is scheduled to > be out soon. > > Brent Taylor > VE1JH > > > Dave Pitzer wrote: > > Richard, > > > > Both you and Reg have given excellent answers and I thank you both. > > > > By the way, you mention directional patterns and nulls. Is there any place I > > can find polar graphs of commercial broadcast station's antenna patterns? > > > > Thanks, > > ====================================== Dave, http://www.nrcdxas.org/catalog/books/ Sounds exactly what you are looking for but may take some time to obtain. In the meantime, the basic groundwave radiation patterns of mediumwave broadcast antennas are either simple circles with the antenna at their centres, or heart-shaped with the antenna at the null. The first occurs when the antenna is a single vertical mast located near the centre of a large populated area. The second occurs when the antenna consists of a pair of masts, which radiate a very broad heart-shaped beam, located on one side of the populated area to be covered. Contour Maps of actual measured field strengths are useful when the basic groundwave patterns are distorted by the terrain, e.g., the existence of mountains, forests, rivers, built-up areas, high-rise cities, or seas, lakes or coastal regions. Radio frequency Field Strengths are usually measured in terms of "millivolts per meter" or in decibels relative to one volt per meter. ---- Reg. Article: 219054 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Antenna gain question References: Message-ID: Date: Sat, 05 Nov 2005 13:38:15 GMT Richard Clark wrote: > Others are encouraged to investigate further to reclaim that missing > dB or to put the horns to my error. Of course, you have deviated considerably from the original infinite number of coherent sources. -- 73, Cecil http://www.qsl.net/w5dxp Article: 219055 of rec.radio.amateur.antenna From: "Asimov" Subject: AM Commercial radio reception Message-ID: References: Date: Sat, 05 Nov 2005 15:11:17 GMT "Dave Pitzer" bravely wrote to "All" (05 Nov 05 02:54:31) --- on the heady topic of "AM Commercial radio reception" DP> From: "Dave Pitzer" DP> Xref: core-easynews rec.radio.amateur.antenna:219693 DP> Why is it that I can received WCBS @ 880kc fairly well at night but DP> WABC @ 770kc suffers from phase distortion like you wouldn't believe! DP> (I'm about 175 miles from both transmitters.) They are both 50 kwatt DP> stations. And why is it that both WBZ (Boston), WBT (Charlotte, NC), DP> WJR (Detroit) and WBBM (Chicago) come in better than either of the New DP> York City stations? DP> Dave P. Perhaps there are a few mountains inbetween you and NYC that cause fringing effects? A*s*i*m*o*v ... Strip-mining prevents forest fires. Article: 219056 of rec.radio.amateur.antenna From: "Caveat Lector" References: Subject: Re: Receiving WWV signal on computer Message-ID: Date: Sat, 5 Nov 2005 07:14:51 -0800 Whoa -- you sed times and ANNOUNCEMENTS the NIST site gives times only If you want the announcements -- try an on-line web receiver - see URL: http://ac6v.com/swl1.htm#WC Also you can download a program that automatically updates your computer clock upon bootup or command so it is accurate within fractions of seconds -- so at anytime just look at your computer clock See URL http://ac6v.com/opaids.htm#CLOCK -- CL -- I doubt, therefore I might be ! "Dave Pitzer" wrote in message news:NdVaf.2183$te3.34552@typhoon.sonic.net... > Ed: > > Perfect!! Thanks! > > Dave > > > "Ed" wrote in message > news:Xns9704BFFD6EFAFspectrumhogstarbandn@207.106.92.175... >> : >> >> > Is there a URL where I can hear WWV time signals & announcments? (I >> > realize there is latency that effect the accuracy but this kis >> > unimportant for my purpose.) >> > >> >> WWV is operated by the National Institute of Standards & Technology. >> >> http://www.nist.gov/ >> >> Time signals are available at: >> >> http://nist.time.gov/ >> >> >> Ed K7AAT > > Article: 219057 of rec.radio.amateur.antenna From: Ralph E Lindberg Subject: Re: 900MHz antenna at sea surface Date: Sat, 05 Nov 2005 07:20:43 -0800 Message-ID: References: <1130962168.655457.263840@f14g2000cwb.googlegroups.com> In article <1130962168.655457.263840@f14g2000cwb.googlegroups.com>, "jmorash" wrote: ... > > thanks for any suggestions > --Jim Morash Jim, I've read through the responses you have had and allow me to inject some real world additions. You see I work for the Navy and we have built things a lot like what you are talking about and getting the antenna some height above the water is a requirement. It's actually rather easy to do. A simple fiberglass mast will do it, counter balancing the added weight is easy, since there needs to be enough mass below the surface to balance some sea state conditions Here is a link to the Newport tracking system http://www.npt.nuwc.navy.mil/autec/barts01.htm This isn't the one we did, but if shows you some ideas The system people I work with developed, use a different buoy system but works almost the same. I did some experiments with antennas (900MHz) just as sea level (OK 3 feet above) and could still get a solid connection at about 1 mile, when I raised them to 6 ft I got a solid connection at 5 miles. Other considerations.. the antenna mast whips a lot and makes recovery (in rough water) a little interesting. There is going to be a switch >from the simple ground-plane antenna to a disc-cone due to the danger the ground radials pose. We also found that putting a LED based flasher on the bouy a real good idea (to see it in low light conditions) -- -------------------------------------------------------- Personal e-mail is the n7bsn but at amsat.org This posting address is a spam-trap and seldom read RV and Camping FAQ can be found at http://www.ralphandellen.us/rv Article: 219058 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: AM Commercial radio reception Date: Sat, 5 Nov 2005 10:37:46 -0600 Message-ID: <23747-436CDFDA-440@storefull-3257.bay.webtv.net> References: Dave P. wrote: "Is there any place I can find polar graphs of commercial broadcast stations?" I have an old book, "Map Book, 540 kc to 1600 kc" published by "Cleveland Insritute of Radio Electronics". In it, WABC is 50 KW non-directional day and night. It shares 770 kc with KOB Albuquerque, 50 KW day and 25 KW night. Also, KUOM Minneapolis and WCAL Nortjhfield are both 5 KW and share the frequency on some schedule between themselves. WNEW St. Louis is on the frequency daytimes only, as is KWA Seattle, 1 KW. XEHB in San Francisco de Oro, Mexico is a 500 watt daytimer on the frequency, as are XELM, 150 watts at Lagos de Morens and XEDI at Queretaro, 1 KW. There is also CMDC, 1 KW at night when it could trouble you in Holquin, Cuba. So, at night there is possible same-channel interderence from New Mexico and Cuba. On 760 kc, you have WJR in Detroit 50 KW non-directional at night and on 780 kc, you have WBBM in Chicago 50 KW nondirectional at night. These non-directional 50KW adjacent channel stations may exercise your AVC. On 880 kc, WCBS has no same-channel night rivals but WLS (World`s Largest Store, Sears in Chicago) on 890 kc, onetime home of "The National Barn Dance", could work your AVC. Also, WWL in New Orleans occupies 870 kc with 50 KW. Good preselection will rid you of adjacent channel interference. I lived in Portugal for years and listened to WCBS nightly. I would rock my tuning from 880 to 870 for WWL during fades for my version of frequency diversity. Both stations carried the same CBS programs. My antenna was a Beverage aimed at New York. The receiver was a Hammarlund SP-600 which had plenty of preselection to avoid adjacent channels. Ed Murrow came in very well. Best regards, Richard Harrison, KB5WZI Article: 219059 of rec.radio.amateur.antenna From: ml Subject: just one vert or horz? Message-ID: Date: Sat, 05 Nov 2005 17:29:50 GMT hi i might have a chance to put up a real antenna on my roof and ponder which type is best"" as i can only do one my choices are either a multi ele beam or a verticle looking for what is 'best' overall for all type not just dx I operate all modes and all bands 160-10 my roof is about 150' off the ground my antenna would be about 30ft off the roof flat surface i was realizing that no one antenna is 'perfect' but wondered generically which would be best overall if you could only get one? thanks Article: 219060 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: Antenna gain question Date: Sat, 5 Nov 2005 18:15:30 +0000 (UTC) Message-ID: References: "Cecil Moore" wrote > Of course, you have deviated considerably from the original > infinite number of coherent sources. ================================ You guys sure know how to enjoy yourselves trying to analyse hypothetical situations. Without any loss in precision, just imagine an isotropic receiver surrounded by 6 equal intensity beams focussed upon it. Forget all about an infinite number of radiators. Or, better still, forget all about the original exceedingly ill-defined question by a leg-puller. You have been trolled. You should be ashamed of yourselves for being taken in by such a question. By the way, the subject of "antenna gains" is amongst the most confusing of all old-wives' tales. It's worse than so-called VSWR measurements on non-existent transmission lines. Or from which ends, or the middle bit, of a dipole does the radiation occur. ---- Reg. Article: 219061 of rec.radio.amateur.antenna From: Jim - NN7K Subject: Re: Receiving WWV signal on computer References: Message-ID: Date: Sat, 05 Nov 2005 18:27:30 GMT Also, if you want to sync your computer to a time standard, do a search on "Dimension 4" when set up, will adjust your computer clock to the reference (and there are several, along with NIST) Jim NN7k Dave Pitzer wrote: > Ed: > > Perfect!! Thanks! > > Dave > > > "Ed" wrote in message > news:Xns9704BFFD6EFAFspectrumhogstarbandn@207.106.92.175... > >>: >> >> >>>Is there a URL where I can hear WWV time signals & announcments? (I >>>realize there is latency that effect the accuracy but this kis >>>unimportant for my purpose.) >>> >> >> WWV is operated by the National Institute of Standards & Technology. >> >> http://www.nist.gov/ >> >> Time signals are available at: >> >> http://nist.time.gov/ >> >> >> Ed K7AAT > > > Article: 219062 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: just one vert or horz? Date: Sat, 5 Nov 2005 18:59:22 +0000 (UTC) Message-ID: References: The best, all round, antenna is undoubtably an approx quarter-wave vertical antenna, or an Inverted-L, on the lowest frequency of interest, with a modest set of a few buried ground radials. An antenna tuner is needed for higher frequencies.. The next best. almost as good, is an approx half-wave dipole at the lowest frequency of interest, fed with openwire line, where no ground system is needed. An antenna tuner is still needed for higher frequencies. ---- Reg. Article: 219063 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: just one vert or horz? References: Message-ID: Date: Sat, 05 Nov 2005 19:38:10 GMT ml wrote: > i was realizing that no one antenna is 'perfect' but wondered > generically which would be best overall if you could only get one? I would suggest a log-periodic beam with a GMC 455ci engine to rotate it. :-) -- 73, Cecil http://www.qsl.net/w5dxp Article: 219064 of rec.radio.amateur.antenna From: Bob Miller Subject: Re: just one vert or horz? Message-ID: References: Date: Sat, 05 Nov 2005 19:39:13 GMT On Sat, 05 Nov 2005 17:29:50 GMT, ml wrote: >hi > > >i might have a chance to put up a real antenna on my roof and ponder >which type is best"" as i can only do one > >my choices are either a multi ele beam or a verticle > >looking for what is 'best' overall for all type not just dx > >I operate all modes and all bands 160-10 If they'll let you put a 160-10m beam on the building, I'd say go for it :-) bob k5qwg > >my roof is about 150' off the ground my antenna would be about 30ft off >the roof flat surface > > >i was realizing that no one antenna is 'perfect' but wondered >generically which would be best overall if you could only get one? > > >thanks Article: 219065 of rec.radio.amateur.antenna From: Owen Duffy Subject: Re: Receiving WWV signal on computer Message-ID: References: Date: Sat, 05 Nov 2005 19:56:47 GMT On Sat, 05 Nov 2005 18:27:30 GMT, Jim - NN7K wrote: >Also, if you want to sync your computer to a time standard, >do a search on "Dimension 4" when set up, will adjust your >computer clock to the reference (and there are several, along >with NIST) Jim NN7k D4 works well, but you don't necessarily need to add software, some operating systems support sntp natively... eg Win 2K and XP. You just have to work out how to activate it. Doesn't everyone syncronise their computer clock nowadays? Owen -- From /dev/null Sat Nov 5 23:51:44 EST 2005 Article: 219066 of rec.radio.amateur.antenna From: Barnacle Bill Newsgroups: rec.radio.amateur.antenna Subject: Re: AM Commercial radio reception Date: Sat, 05 Nov 2005 20:22:19 -0000 Organization: Spouter Inn Gang Message-ID: <11mq53r42dgl488@corp.supernews.com> References: Reply-To: /dev/null User-Agent: slrn/0.9.8.1 (Linux) X-Complaints-To: abuse@supernews.com Lines: 13 Path: news1.isis.unc.edu!canoe.uoregon.edu!newshub.sdsu.edu!newsfeed.news2me.com!newsfeed2.easynews.com!newsfeed1.easynews.com!easynews.com!easynews!sn-xit-03!sn-xit-08!sn-post-02!sn-post-01!supernews.com!corp.supernews.com!not-for-mail Xref: news1.isis.unc.edu rec.radio.amateur.antenna:219066 On 2005-11-05, Dave Pitzer wrote: > Why is it that I can received WCBS @ 880kc fairly well at night but WABC @ > 770kc suffers from phase distortion like you wouldn't believe! (I'm about > 175 miles from both transmitters.) They are both 50 kwatt stations. And why > is it that both WBZ (Boston), WBT (Charlotte, NC), WJR (Detroit) and WBBM > (Chicago) come in better than either of the New York City stations? > > Dave P. > > WBZ in Boston is a clear channel station. I don't think they have any pattern restrictions; they run 50kw 24/7. Article: 219067 of rec.radio.amateur.antenna From: John Ferrell Subject: Re: just one vert or horz? Message-ID: <0d6qm1923s8hcuva80it3r39uoer7ovm49@4ax.com> References: Date: Sat, 05 Nov 2005 20:50:07 GMT I really like my Cushcraft A3S with the 40 meter option. However, it does not cover the "new bands" or 80/160. If you were to mount it 20 feet or more above the roof it would probably work well. I am in the throws of trying to figure out what to do about 80 & 160 myself. Any way you do it you will have to trade physical size for band width. Now would be a good time to start considering what you are going to do about lightning protection though. John Ferrell, W8CCW On Sat, 05 Nov 2005 17:29:50 GMT, ml wrote: >hi > > >i might have a chance to put up a real antenna on my roof and ponder >which type is best"" as i can only do one > >my choices are either a multi ele beam or a verticle > >looking for what is 'best' overall for all type not just dx > >I operate all modes and all bands 160-10 > >my roof is about 150' off the ground my antenna would be about 30ft off >the roof flat surface > > >i was realizing that no one antenna is 'perfect' but wondered >generically which would be best overall if you could only get one? > > >thanks Article: 219068 of rec.radio.amateur.antenna From: ml Subject: tnx: just one vert or horz? References: Message-ID: Date: Sat, 05 Nov 2005 21:11:00 GMT In article , "Reg Edwards" wrote: > The best, all round, antenna is undoubtably an approx quarter-wave > vertical antenna, or an Inverted-L, on the lowest frequency of > interest, with a modest set of a few buried ground radials. An > antenna tuner is needed for higher frequencies.. > > The next best. almost as good, is an approx half-wave dipole at the > lowest frequency of interest, fed with openwire line, where no ground > system is needed. An antenna tuner is still needed for higher > frequencies. > ---- > Reg. thanks to all that replied seems a good verticle is going to win, and avoids the rotor complexity i already have a dipole works pretty good but i have nothing to compare it to so a verticle might afford me some interesting comparisons /experimenting Article: 219069 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: tnx: just one vert or horz? References: Message-ID: <4x9bf.24577$6e1.6918@newssvr14.news.prodigy.com> Date: Sat, 05 Nov 2005 21:31:44 GMT ml wrote: > i already have a dipole works pretty good but i have nothing to > compare it to so a verticle might afford me some interesting > comparisons /experimenting You will be disappointed in two directions and amazed in the other two directions. :-) -- 73, Cecil http://www.qsl.net/w5dxp Article: 219070 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: tnx: just one vert or horz? Date: Sat, 5 Nov 2005 23:54:11 +0000 (UTC) Message-ID: References: <4x9bf.24577$6e1.6918@newssvr14.news.prodigy.com> "Cecil Moore" wrote > You will be disappointed in two directions and amazed in the > other two directions. :-) ================================== Cec, with the verticals and inverted-L's and dipoles I have ever erected, I have never noticed much difference between one direction and another except when my house or the neighbour's house got in the way. And most of the difference was just my imagination. Simple antennas, in the average amateur's environment, are effectively omni-directional in all planes without any nulls. I have never had any silly objections to radiation from the feedline, although I have never been certain that I ever had any. If I ever made made any propagation calculations I always treated my antennas as being isotropes. When the calculating uncertainty is plus or minus 10 dB who cares anyway? I am the last person to suffer from delusions of accuracy. Yet I am a firm believer in Kelvin. I once made a balun. It was in the feedline for 24 hours. It didn't make a scrap of difference to anything except weight. I still have it. The workmanship and neatness of the windings around the ferrite ring was too good to throw away. I've just noticed this message is in terms of a history. I am 80 this month. ---- Reg, G4FGQ. Article: 219071 of rec.radio.amateur.antenna From: "Earl Needham" Subject: Re: Receiving WWV signal on computer Date: Sat, 5 Nov 2005 17:42:09 -0700 Message-ID: <11mqkb184dnnfa2@corp.supernews.com> References: "Owen Duffy" wrote in message news:of3qm1dee4mrpqvciouul2vnkvct26crbm@4ax.com... > On Sat, 05 Nov 2005 18:27:30 GMT, Jim - NN7K > wrote: > > >Also, if you want to sync your computer to a time standard, > >do a search on "Dimension 4" when set up, will adjust your > >computer clock to the reference (and there are several, along > >with NIST) Jim NN7k > > D4 works well, but you don't necessarily need to add software, some > operating systems support sntp natively... eg Win 2K and XP. You just > have to work out how to activate it. I must be the only one still using Windows 2000 Pro at my home. It works well, so I'm in no hurry to "upgrade" to anything else. But HOW do you make W2K support sntp? I've never found that option, and I use an external program to make it work. Thanks, Earl -- Earl Needham Clovis, New Mexico USA Article: 219072 of rec.radio.amateur.antenna Date: Sat, 05 Nov 2005 18:47:53 -0600 From: Tom Ring Subject: Re: AM Commercial radio reception References: <23747-436CDFDA-440@storefull-3257.bay.webtv.net> Message-ID: <436d52c4$0$3760$39cecf19@news.twtelecom.net> Richard Harrison wrote: > very well. > > Best regards, Richard Harrison, KB5WZI > Slight change of subject, WCCO 830 and a couple others I've noticed, now have a tremendous amount of digital sounding crap around them that completely obscures stations such as KOA. Is this the new digital radio wonder weapon that I'm supposed to love? tom K0TAR Article: 219073 of rec.radio.amateur.antenna From: Henry Subject: Lunch Tomorrow Date: Sat, 05 Nov 2005 18:48:47 -0600 Message-ID: Be here before 12:00 for lunch. CU then. Love Dad Article: 219074 of rec.radio.amateur.antenna From: Ron Subject: Re: Antenna gain question References: Message-ID: Date: Sun, 06 Nov 2005 01:18:18 GMT > Or, better still, forget all about the original exceedingly > ill-defined question by a leg-puller. You have been trolled. You > should be ashamed of yourselves for being taken in by such a question. Hello Reg, I wrote the original question. It may be dumb but it was not facetious. I am not a troll. Happy birthday, Ron, W4TQT Article: 219075 of rec.radio.amateur.antenna From: Owen Duffy Subject: Re: Receiving WWV signal on computer Message-ID: <17nqm1dn6askmh729vdghed48qn724vsot@4ax.com> References: <11mqkb184dnnfa2@corp.supernews.com> Date: Sun, 06 Nov 2005 01:51:19 GMT On Sat, 5 Nov 2005 17:42:09 -0700, "Earl Needham" wrote: > But HOW do you make W2K support sntp? I've never found that option, and >I use an external program to make it work. You configure and start the Time32 service. These articles should be helpful: http://support.microsoft.com/support/kb/articles/Q246/1/45.ASP http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnw2kmag01/html/TimeWin2K.asp http://support.microsoft.com/kb/223184/ If after you have done the net time /setsntp thing and started the service and it still doesn't work, it is because some registry settings are not correct. I have a .reg file with them in, but not with me. See the second article. IIRC XP is just as unornery. For sntp servers, have a browse to pool.ntp.org. Owen -- Article: 219076 of rec.radio.amateur.antenna From: "Crazy George" References: <6487-436C4D06-493@storefull-3252.bay.webtv.net> Subject: Re: AM Commercial radio reception Date: Sat, 5 Nov 2005 20:12:08 -0600 Message-ID: <436d6a27_3@news1.prserv.net> > In the meantime, the basic groundwave radiation patterns of mediumwave > broadcast antennas are either simple circles with the antenna at their > centres, or heart-shaped with the antenna at the null. > > The first occurs when the antenna is a single vertical mast located > near the centre of a large populated area. > > The second occurs when the antenna consists of a pair of masts, which > radiate a very broad heart-shaped beam, located on one side of the > populated area to be covered. > ---- > Reg. > > Reg: I'm afraid you're way behind the practice on this one. In the US, there are many 4, 5 and 6 tower arrays providing as many nulls to protect co-channel stations. The UK got off easy with nationalized broadcasting, where the frequency and location was dictated by the government, and none of that nasty capitalism interfered. Here, the commercial interests are still fighting it out. Check and see if the KLIF website shows their pattern from a linear array of 5 towers just outside Dallas. -- Crazy George W5VPQ My real address is my ham call ARRL.NET The ATTGlobal is a SPAM trap. Article: 219077 of rec.radio.amateur.antenna From: "Crazy George" References: <23747-436CDFDA-440@storefull-3257.bay.webtv.net> <436d52c4$0$3760$39cecf19@news.twtelecom.net> Subject: Re: AM Commercial radio reception Date: Sat, 5 Nov 2005 20:18:48 -0600 Message-ID: <436d6ba6_1@news1.prserv.net> "Tom Ring" wrote in message news:436d52c4$0$3760$39cecf19@news.twtelecom.net... > Richard Harrison wrote: > > > very well. > > > > Best regards, Richard Harrison, KB5WZI > > > > Slight change of subject, WCCO 830 and a couple others I've noticed, now > have a tremendous amount of digital sounding crap around them that > completely obscures stations such as KOA. Is this the new digital radio > wonder weapon that I'm supposed to love? > > tom > K0TAR > You bet!!!! -- Crazy George W5VPQ My real address is my ham call ARRL.NET The ATTGlobal is a SPAM trap. Article: 219078 of rec.radio.amateur.antenna Subject: Re: Receiving WWV signal on computer From: Ed References: <11mqkb184dnnfa2@corp.supernews.com> Message-ID: Date: Sun, 06 Nov 2005 02:33:07 GMT > But HOW do you make W2K support sntp? I've never found that > option, and > I use an external program to make it work. > > Thanks, > Earl Interesting info at: http://msdn.microsoft.com/library/default.asp?url=/library/en- us/dnw2kmag01/html/TimeWin2K.asp Ed K7AAT Article: 219079 of rec.radio.amateur.antenna Date: Sat, 05 Nov 2005 21:14:53 -0600 From: Tom Ring Subject: My antennas are on QRZ's cover Message-ID: <436d752d$0$32205$39cecf19@news.twtelecom.net> I wouldn't have voted for them, but my friend, Geoff KC0FXY, did take a nice shot. And I guess QRZ thought so too. https://secure.qrz.com/store/qrz_cd.html So my 6 meter beams are on the 2005-2006 cover. To explain the shot, the lower beam is a fixed 3 element which is meant to cover the Minneapolis/St Paul metro area. The 4 over 4 above it is rotarable. tom K0TAR Article: 219080 of rec.radio.amateur.antenna Date: Sat, 05 Nov 2005 21:43:57 -0600 From: Tom Ring Subject: Re: My antennas are on QRZ's cover References: <436d752d$0$32205$39cecf19@news.twtelecom.net> Message-ID: <436d7c07$0$3756$39cecf19@news.twtelecom.net> Tom Ring wrote: > The 4 over 4 above it is rotarable. And I don't type well. Article: 219081 of rec.radio.amateur.antenna From: "Dave Pitzer" References: Subject: Re: AM Commercial radio reception Message-ID: Date: Sun, 06 Nov 2005 04:01:28 GMT Thanks to you all for your excellent information DP "Dave Pitzer" wrote in message news:H9Vaf.2182$te3.34552@typhoon.sonic.net... > Why is it that I can received WCBS @ 880kc fairly well at night but WABC @ > 770kc suffers from phase distortion like you wouldn't believe! (I'm about > 175 miles from both transmitters.) They are both 50 kwatt stations. And why > is it that both WBZ (Boston), WBT (Charlotte, NC), WJR (Detroit) and WBBM > (Chicago) come in better than either of the New York City stations? > > Dave P. > > Article: 219082 of rec.radio.amateur.antenna From: Henry Subject: Re: Lunch Tomorrow Date: Sat, 05 Nov 2005 23:07:34 -0600 Message-ID: References: Dave wrote: > "Henry" wrote in message > news:dkjjsu031g4@enews3.newsguy.com... > >>Be here before 12:00 for lunch. >> >>CU then. >> >>Love >> >>Dad > > > what you having?? > > ROTFL I was in this newsgroup when I thought I was in my email program and I sent the message to my son. I called him later and he said he didn't get the email. I'll try to be more carefull, but it sure is funny to me. :-) Henry Article: 219083 of rec.radio.amateur.antenna From: Stananger <********@***.***> Subject: Re: Lunch Tomorrow References: Message-ID: <_Cgbf.10253$Ny6.9301@trnddc06> Date: Sun, 06 Nov 2005 05:35:54 GMT Henry wrote: > Dave wrote: >> "Henry" wrote in message >> news:dkjjsu031g4@enews3.newsguy.com... >> >>>Be here before 12:00 for lunch. >>> >>>CU then. >>> >>>Love >>> >>>Dad >> >> >> what you having?? >> >> > ROTFL I was in this newsgroup when I thought I was in my email > program and I sent the message to my son. I called him later and he > said he didn't get the email. I'll try to be more carefull, but it > sure is funny to me. :-) > > Henry So whats for lunch? you still didnt tell us! Article: 219085 of rec.radio.amateur.antenna From: "David G. Nagel" Subject: Re: Lunch Tomorrow Date: Sun, 06 Nov 2005 01:49:13 -0600 Message-ID: <11mrdc11nfj4t56@corp.supernews.com> References: <_Cgbf.10253$Ny6.9301@trnddc06> Stananger wrote: > Henry wrote: > > >>Dave wrote: >> >>>"Henry" wrote in message >>>news:dkjjsu031g4@enews3.newsguy.com... >>> >>> >>>>Be here before 12:00 for lunch. >>>> >>>>CU then. >>>> >>>>Love >>>> >>>>Dad >>> >>> >>>what you having?? >>> >>> >> >>ROTFL I was in this newsgroup when I thought I was in my email >>program and I sent the message to my son. I called him later and he >>said he didn't get the email. I'll try to be more carefull, but it >>sure is funny to me. :-) >> >>Henry > > > So whats for lunch? you still didnt tell us! And where do we meet? Article: 219087 of rec.radio.amateur.antenna From: ml Subject: birthday/radition: tnx: just one vert or horz? References: <4x9bf.24577$6e1.6918@newssvr14.news.prodigy.com> Message-ID: Date: Sun, 06 Nov 2005 12:18:24 GMT happy birthday if you were around nyc i'd buy you a cake so if i understood your below, your saying you had a dipole in some direction lets say n s and your average signals came in same as your E W dipole? or say if i had a nice multielement optibeam on 20m and i heard a week signal started to turn the beam all around findng max signal East if i switched to my verticle you'd hypothise it'd come in about the same further if your below was true then wouldn't turning the beam mean my signal would always be about the same? or was it just a dipole vs verticle comparison that i spazed out on ? In article , "Reg Edwards" wrote: > "Cecil Moore" wrote > > You will be disappointed in two directions and amazed in the > > other two directions. :-) > ================================== > > Cec, with the verticals and inverted-L's and dipoles I have ever > erected, I have never noticed much difference between one direction > and another except when my house or the neighbour's house got in the > way. And most of the difference was just my imagination. > > Simple antennas, in the average amateur's environment, are effectively > omni-directional in all planes without any nulls. I have never had any > silly objections to radiation from the feedline, although I have never > been certain that I ever had any. > > If I ever made made any propagation calculations I always treated my > antennas as being isotropes. When the calculating uncertainty is plus > or minus 10 dB who cares anyway? I am the last person to suffer from > delusions of accuracy. Yet I am a firm believer in Kelvin. > > I once made a balun. It was in the feedline for 24 hours. It didn't > make a scrap of difference to anything except weight. I still have > it. The workmanship and neatness of the windings around the ferrite > ring was too good to throw away. > > I've just noticed this message is in terms of a history. I am 80 this > month. > ---- > Reg, G4FGQ. Article: 219088 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: tnx: just one vert or horz? References: <4x9bf.24577$6e1.6918@newssvr14.news.prodigy.com> Message-ID: Date: Sun, 06 Nov 2005 13:28:49 GMT Reg Edwards wrote: > Simple antennas, in the average amateur's environment, are effectively > omni-directional in all planes without any nulls. My rotatable 33 ft. dipole at 50 ft. is a pretty simple antenna, Reg. It is not omni-directional. Rotating it can make about two S-units difference on 20m and up to about 4 S-units difference on 10m. > I've just noticed this message is in terms of a history. I am 80 this > month. I hear Scorpio is the sexiest sign in the Zodiac. Happy Birthday, Reg, and many happy returns. My 95 year old aunt, a mile away in the nursing home, says you are just a young sprout. -- 73, Cecil http://www.qsl.net/w5dxp Article: 219089 of rec.radio.amateur.antenna From: "Earl Needham" Subject: Re: Receiving WWV signal on computer Date: Sun, 6 Nov 2005 07:38:55 -0700 Message-ID: <11ms5c0299gjh37@corp.supernews.com> References: <11mqkb184dnnfa2@corp.supernews.com> <17nqm1dn6askmh729vdghed48qn724vsot@4ax.com> "Owen Duffy" wrote in message news:17nqm1dn6askmh729vdghed48qn724vsot@4ax.com... > On Sat, 5 Nov 2005 17:42:09 -0700, "Earl Needham" > wrote: > > > But HOW do you make W2K support sntp? I've never found that option, and > >I use an external program to make it work. > > You configure and start the Time32 service. These articles should be > helpful: > > http://support.microsoft.com/support/kb/articles/Q246/1/45.ASP > > http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnw2kmag01/html/TimeWin2K.asp > > http://support.microsoft.com/kb/223184/ Wow, I didn't know you could do that! This is handy indeed! 7 3 Earl KD5XB -- Earl Needham Clovis, New Mexico USA Article: 219090 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: tnx: just one vert or horz? Date: Sun, 6 Nov 2005 15:01:05 +0000 (UTC) Message-ID: References: <4x9bf.24577$6e1.6918@newssvr14.news.prodigy.com> "Cecil wrote > > My rotatable 33 ft. dipole at 50 ft. is a pretty simple antenna, Reg. > It is not omni-directional. Rotating it can make about two S-units > difference on 20m and up to about 4 S-units difference on 10m. ===================================== Cec, in the broad expanses of Texas no doubt it has a similar performance at all other frequencies too. But I suggest a 33-feet rotatable dipole does not make you an average amateur. Thanks for birthday greetings all the way from Texas. The World sure is getting to be a small place! The Internet appears to have shrunk it more than radio ever did. ---- Yours, Reg, G4FGQ Article: 219091 of rec.radio.amateur.antenna Message-ID: <3130303038373835436CDD2E91@zetnet.co.uk> Date: Sat, 5 Nov 2005 16:26:22 GMT From: Dave Piggin Subject: Re: Question on shooting a line References: <1130633563.967446.51040@g49g2000cwa.googlegroups.com> <313030303837383543660A4434@zetnet.co.uk> Why not just use the rod and reel? Admittedly some can throw farther than they can cast. I doubt there are very many people who can either throw, or cast a line, at 70 feet, over a particular branch of a rather densely packed conifer tree. I can do it, however, with a slingshot. A bow or crossbow would be even better, I'll admit. Which is why I recommend using my described method, as you can "sight" up your target. Easy really. Dave. d:-)) -- Amateur Radio Call Sign M1BTI, Located in Manchester England. Locator square IO83TK Chairman Of Trafford Radio Club. Club Call Signs G0TRG & M1BBP Located at Umist, University Of Manchester Institute For Science And Technology Share What You Know, Learn What You Dont. Article: 219092 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: tnx: just one vert or horz? References: <4x9bf.24577$6e1.6918@newssvr14.news.prodigy.com> Message-ID: Date: Sun, 06 Nov 2005 15:24:13 GMT Reg Edwards wrote: > Cec, in the broad expanses of Texas no doubt it has a similar > performance at all other frequencies too. But I suggest a 33-feet > rotatable dipole does not make you an average amateur. Point is that if it wasn't rotatable, it would make me average, and I would be missing out. -- 73, Cecil http://www.qsl.net/w5dxp Article: 219093 of rec.radio.amateur.antenna From: w4sef@bellsouth.net (Steven Fritts) Subject: Re: rf induced fire in the trees? Message-ID: <436e2448.565203@newsgroups.bellsouth.net> References: <6nkrm1p8pr0ofhacr5nssjtbsfl06776d4@4ax.com> Date: Sun, 06 Nov 2005 15:42:49 GMT VERY unlikely you will set the tree on fire...you would have to be running several kw at the very least to even begin to start a fire! Steve On Sun, 06 Nov 2005 10:02:10 GMT, jimg wrote: >hi. i'm about to be a new ham. i hv only 1 chance for an antenna for >80m (or 40, even 20). there's a 120' oak tree in the yard with 70' >clear on either side. so i thought a ladder-line center-fed inverted >vee dipole (63' per leg, 14ga teflon insulated stranded) would be my >best bet...so at 100W, even 600W ...am i going to set the tree on >fire? any ideas on how to keep bad things from happening? thank you >very much? > >jimg >jimg >Oregon >USA Article: 219094 of rec.radio.amateur.antenna Message-ID: <436E3244.8650B249@shaw.ca> From: Irv Finkleman Subject: Re: rf induced fire in the trees? References: <6nkrm1p8pr0ofhacr5nssjtbsfl06776d4@4ax.com> <436e2448.565203@newsgroups.bellsouth.net> Date: Sun, 06 Nov 2005 16:41:38 GMT Steven Fritts wrote: > > VERY unlikely you will set the tree on fire...you would have to be > running several kw at the very least to even begin to start a fire! > > Steve > > On Sun, 06 Nov 2005 10:02:10 GMT, jimg wrote: > > >hi. i'm about to be a new ham. i hv only 1 chance for an antenna for > >80m (or 40, even 20). there's a 120' oak tree in the yard with 70' > >clear on either side. so i thought a ladder-line center-fed inverted > >vee dipole (63' per leg, 14ga teflon insulated stranded) would be my > >best bet...so at 100W, even 600W ...am i going to set the tree on > >fire? any ideas on how to keep bad things from happening? thank you > >very much? > > > >jimg > >jimg > >Oregon > >USA As long as the outer ends of the Vee are out of the branches you will be OK. Irv VE6BP -- -------------------------------------- Diagnosed Type II Diabetes March 5 2001 Beating it with diet and exercise! 297/215/210 (to be revised lower) 58"/43"(!)/44" (already lower too!) -------------------------------------- Visit my HomePage at http://members.shaw.ca/finkirv/index.html Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/index.htm Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/index.htm -------------------- Irv Finkleman, Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP Calgary, Alberta, Canada Article: 219095 of rec.radio.amateur.antenna Subject: Re: rf induced fire in the trees? From: Ed References: <6nkrm1p8pr0ofhacr5nssjtbsfl06776d4@4ax.com> Message-ID: Date: Sun, 06 Nov 2005 17:38:26 GMT > hi. i'm about to be a new ham. i hv only 1 chance for an antenna for > 80m (or 40, even 20). there's a 120' oak tree in the yard with 70' > clear on either side. so i thought a ladder-line center-fed inverted > vee dipole (63' per leg, 14ga teflon insulated stranded) would be my > best bet...so at 100W, even 600W ...am i going to set the tree on > fire? any ideas on how to keep bad things from happening? thank you > very much? > My own opinion, I do not like Oak trees for antenna work.... when the leaves are on, they are difficult, to say the least. However, with winter here, I'm sure you will be able to configure the apex of your inverted V OK in that big tree. Have you actually considered the amount of real estate you need for an Invertet V for 75M ? With a center height of only 40 feet, your 1/4 wave legs will extend out barely over about 47 feet each side of center. You may be able to do what you are thinking with a simple center mast instead of using the Oak tree. It certainly would make working on your antenna and changing things a bit easier. Good luck, either case. Ed K7AAT in Oregon, too. Article: 219096 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: rf induced fire in the trees? References: <6nkrm1p8pr0ofhacr5nssjtbsfl06776d4@4ax.com> <436e2448.565203@newsgroups.bellsouth.net> <436E3244.8650B249@shaw.ca> Message-ID: Date: Sun, 06 Nov 2005 18:38:39 GMT Irv Finkleman wrote: > As long as the outer ends of the Vee are out of the branches you will be OK. That works for 80m but what about 40m where the voltage maximum point is at the feedpoint? -- 73, Cecil http://www.qsl.net/w5dxp Article: 219097 of rec.radio.amateur.antenna From: Bob Miller Subject: Re: rf induced fire in the trees? Message-ID: References: <6nkrm1p8pr0ofhacr5nssjtbsfl06776d4@4ax.com> Date: Sun, 06 Nov 2005 18:41:32 GMT On Sun, 06 Nov 2005 10:02:10 GMT, jimg wrote: >hi. i'm about to be a new ham. i hv only 1 chance for an antenna for >80m (or 40, even 20). there's a 120' oak tree in the yard with 70' >clear on either side. so i thought a ladder-line center-fed inverted >vee dipole (63' per leg, 14ga teflon insulated stranded) would be my >best bet...so at 100W, even 600W ...am i going to set the tree on >fire? any ideas on how to keep bad things from happening? thank you >very much? > >jimg >jimg >Oregon >USA I have an 80 meter dipole running through three trees; I use a standard tree trimmer (reach about 20'-25') to keep the wires pretty much in the clear. bob k5qwg Article: 219098 of rec.radio.amateur.antenna From: "Rod Maupin" Subject: Re: Selecting a rotator Date: Sun, 6 Nov 2005 15:17:23 -0800 Message-ID: <11mt3o3to3jk2a3@corp.supernews.com> References: <11mn6bmit0a6e2d@corp.supernews.com> Tam, I see what you mean. I was leaning towards the Yaesu G-450A rotator instead of the Hy-Gain AR-40. I read a less than favorable review on that one. However, I also read some unfavorable reviews on the Yaesu G-450A. People's main complaint was about the buttons on the control box not being very good. Actually, the VHF/UHF antenna I was thinking of putting up is only 1 sq.ft., I was just using 10 sq.ft. as an example. I did read about the thrust bearing and agree with you on that. Rod KI7CQ Article: 219099 of rec.radio.amateur.antenna From: "RB" Subject: how to check balun Message-ID: Date: Sun, 6 Nov 2005 17:17:51 -0600 Just put up a 140' dipole with 450 ohm ladderline feed. I'm using an unbalanced tuner with a Spi-Ro 1:1 balun on the output side of the tuner. The balun is one of those designed to be used right at the center feed point of the antenna, with coax as the feedline. I think it should work out fine being directly at the output of the tuner, with ladderline going up to the antenna. However, there is some disconnect between the rig and antenna. I suspect my balun may be bad internally. What's a good quick and dirty check with an ohmeter (don't know if these baluns are current or voltage types, so maybe include a checkout procedure for both kinds). I'm just starting to fault isolate. Since the balun is a new link in the chain from rig to antenna, it's my first suspect. Article: 219100 of rec.radio.amateur.antenna From: "Bill" Subject: What Would You Do?? Message-ID: <89xbf.14860$td.1301@bignews3.bellsouth.net> Date: Sun, 6 Nov 2005 19:27:00 -0500 Years ago I cleared a 200 foot path in among some hard woods....Needed to practice my high irons.... But Now...lets put up a monster antenna.. For high bands 17 - 20 meters. In this path I've got two 120 foot towers in line with Europe. The towers are 500 feet apart......Its pretty well open on the sides I can easily run a cable between them and then hang what...??? Give me your dream antenna...or your best shot!!! Thanks, Bill http://www.kc4pe.com/amateurshack.htm Article: 219101 of rec.radio.amateur.antenna From: "Ralph Mowery" References: <11mn6bmit0a6e2d@corp.supernews.com> <11mt3o3to3jk2a3@corp.supernews.com> Subject: Re: Selecting a rotator Message-ID: Date: Mon, 07 Nov 2005 00:26:56 GMT "Rod Maupin" wrote in message news:11mt3o3to3jk2a3@corp.supernews.com... > Tam, > > I see what you mean. I was leaning towards the Yaesu G-450A rotator instead > of the Hy-Gain AR-40. I read a less than favorable review on that one. > However, I also read some unfavorable reviews on the Yaesu G-450A. People's > main complaint was about the buttons on the control box not being very good. > > Actually, the VHF/UHF antenna I was thinking of putting up is only 1 sq.ft., > I was just using 10 sq.ft. as an example. I did read about the thrust > bearing and agree with you on that. > > Rod KI7CQ > > The probably make things with less quality now than they did about 40 years ago. I had an 11 element 2 meter CC beam ( please no comments about that antenna) on a AR 33 that was even less heavy duty than the ar40 was at that time. The rotator has been turning a big TV antenna for the last 30 years. For a small vhf antenna I would look around for a used (doubt you could find a new) Alliance U-100. It should be about $ 150 or more less than the ar40. I have one mounted in a tower (no thrust bearing) but the mast goes through 2 plates about 2 feet apart and the hole in them is only about 1/2 inches bigger than the mast and it has been turning a 8 element 14 foot boom 2 meter , 22 element 440 and an 8 element 10 foot boom 220 mhz antenna for about 10 years. Article: 219102 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: how to check balun Date: Sun, 06 Nov 2005 16:34:16 -0800 Message-ID: <11mt89rl4nm5a17@corp.supernews.com> References: With a current balun, you should have continuity from the feedline conductors to the antenna conductors just as though the balun were a couple of pieces of wire connecting the feedline directly to the antenna. There shouldn't be any continuity from one side of the antenna or feedline to the other. A correctly operating voltage balun will show continuity between any pair of conductors, input to input, output to output, or input to output, just as though they were all shorted together inside. If there's an internal short where it shouldn't be, you won't be able to determine it with an ohmmeter. But you'd be able to see an open connection. You won't be able to tell a short-circuited current balun from a normally operating voltage balun with an ohmmeter, either. Using the balun as you are might cause its destruction. If the impedance seen at the input of the ladderline is very high (which is particularly possible if you're using the dipole on multiple bands), the voltage appearing across the balun might well be more than it's designed to handle. There are also likely to be common mode impedances on some bands that will be too high for the balun to be effective. Moving the balun to the antenna will change the bands where those conditions exist, but won't necessarily alleviate them -- assuming you're using the dipole on multiple bands, that is. You might consider taking a look at Cecil's web site for some alternatives. Roy Lewallen, W7EL RB wrote: > Just put up a 140' dipole with 450 ohm ladderline feed. > > I'm using an unbalanced tuner with a Spi-Ro 1:1 balun on the output side of > the tuner. The balun is one of those designed to be used right at the > center feed point of the antenna, with coax as the feedline. I think it > should work out fine being directly at the output of the tuner, with > ladderline going up to the antenna. > > However, there is some disconnect between the rig and antenna. I suspect my > balun may be bad internally. What's a good quick and dirty check with an > ohmeter (don't know if these baluns are current or voltage types, so maybe > include a checkout procedure for both kinds). > > I'm just starting to fault isolate. Since the balun is a new link in the > chain from rig to antenna, it's my first suspect. > > Article: 219103 of rec.radio.amateur.antenna From: "RB" References: <11mt89rl4nm5a17@corp.supernews.com> Subject: Re: how to check balun Message-ID: <_lybf.2649$kd.2028@bignews4.bellsouth.net> Date: Sun, 6 Nov 2005 19:48:27 -0600 Wow! Good info, Roy. Thanks. That should get me going, at least.