Article: 221748 of rec.radio.amateur.antenna From: John Ferrell Subject: Re: Smith Chart vs JAVA Message-ID: References: <1pifv1l0gc9ji32ipa3os3gfma0en7nvn5@4ax.com> Date: Mon, 20 Feb 2006 13:27:29 GMT It also fails to run as a download from the XP Home Laptop (also IE 6). I need to run the most popular browser so that I can verify the operation of the web sites I maintain and to stay familiar with my client's configurations. I used to keep Netscape available to verify anther browser but have opted for a Linux (USE 10) machine as an alternate lately. It is unfortunate that Microsoft has elected to shun Java but I won't let that become my problem. Thanks for all the help, I choose to outflank the Java issue and get back to the Smith Charts! >And it works fine using Camino on my G4 PowerMac. (Camino is rather like >Firefox, but it make direct use of Macintosh system calls and thus is >much, much faster than Firefox.) I had the thing working about 3 seconds >after downloading it. Java is Java is Java and should be completely >platform-independent. But if the original poster is using Internet >Exploder, that may the be problem. The mozilla.org browsers are safe, >they have Java built-in, and anyway he should replace IE with Firefox >for his computer's health's sake and not just to make Java work in the >browser. > >David, ex-W8EZE John Ferrell W8CCW Article: 221749 of rec.radio.amateur.antenna From: Dot Subject: Re: Usenet Kook Alert .... Lyle Blake Message-ID: References: <1140404823.199601.294020@g43g2000cwa.googlegroups.com> Date: Mon, 20 Feb 2006 08:11:51 -0500 On Sun, 19 Feb 2006 20:50:19 -0800, "Sal M. Onella" wrote: > > wrote in message >news:1140404823.199601.294020@g43g2000cwa.googlegroups.com... >Dot will need to make postings a lot nastier to be considered by most to be >"a truly viscious [sic] Usenet kook." HIs post seemed ordinary enough. I see my stalker made it here, with the usual lies and hatred, in short order. I am here to talk about antennas... she's here to try to turn you all against me, as she's done a hundred times before. If any of you are uncomfortable with my continued presence just say so and I shall head back off to places nether to mess with radios, talk to some people and otherwise enjoy the hobby... >However, will watch for incipient flame wars and take kill-file action, as >needed. Not to worry... My rules are real simple. 1) You play fair and I play fair. 2) I never back down from bullies. That is... I don't start fights but I do tend to finish them. Article: 221750 of rec.radio.amateur.antenna From: Bob Bob Subject: Re: Low power 5w FM Transmitter antenna References: <1140420029.713791.128680@g47g2000cwa.googlegroups.com> Message-ID: Date: Mon, 20 Feb 2006 07:19:48 -0600 Hi Sam Keeping this technical rather than legal! I think the cheapest/easiest way to do this is mount a quarter wave whip on top of one of the (many?) corrugated iron building roofs. There are many ways to start this off. I guess that given proximity of resources etc a cut down CB mobile base and whip would be a viable option. I am talking about a fibreglass or stainless steel antenna that initially would be about 9ft to start with. The length of the whip would be roughly 300/freq/4 but tuning it with an SWR measuring device would be a good thing to do. Cheers Bob VK2YQA samuel.lawrence@optusnet.com.au wrote: > > Hello, > > A friend of mine live in outback NSW and wants to install a 5w FM Article: 221751 of rec.radio.amateur.antenna From: "Frank" References: <2uCdnZM2ip4FCXLenZ2dnUVZ_s6dnZ2d@comcast.com> <8OPHf.9448$W31.154@edtnps90> <43F01340.8010707@comcast.net> <800If.344$fQ1.22@clgrps12> Subject: Re: diff in coils between c_poise and vertload ?? Message-ID: Date: Mon, 13 Feb 2006 15:43:38 GMT "Dan Richardson" wrote in message news:t161v11jcf97fvfv5nphs2co0vgpm4e4ul@4ax.com... > On Mon, 13 Feb 2006 13:41:24 GMT, "Frank" > wrote: > >>NEC indicates the coil is 123 uH, and a Q of 4471 at 3.8 MHz. You would >>certainly have to silver plate the coil in order to maintain such a Q. >>The >>formation of copper oxide will cause Q degradation over time -- despite >>what >>some people seem to think. > > It is not just what "some people" think. > > Check out: http://k6mhe.com/n7ws/Plating.pdf > > 73, > Danny, K6MHE Thanks Danny, Interesting paper. It certainly points out problems with silver plating. I must say I have never attempted to measure the Qs of inductors with and without plating, but it is something to think about. My point was more about the effects of copper oxide on inductor Q. It makes me think that the best way to prevent the build up of oxide is to use some kind of low-loss insulating material on the surface of the copper. 73, Frank Article: 221752 of rec.radio.amateur.antenna From: "Frank's Basement 2" References: <1140274674.116569.208960@g47g2000cwa.googlegroups.com> <43F74956.2060207@comcast.net> <43F79966.3070004@comcast.net> <43F8C006.7030806@comcast.net> <43F95032.1000908@comcast.net> Subject: Re: using coax shield to create a loading coil ? Message-ID: Date: Mon, 20 Feb 2006 16:26:57 GMT Dan, even more questions: I don't understand the relationship of radial length to height. c_poise seems to allow anything. What is the "H" of a loading coil? Frank "dansawyeror" wrote in message news:43F95032.1000908@comcast.net... > Follow up: > > One of the not so apparent results of Reg's program is the relationship of > radial length to height. I chose 2 meters because they were only .7 meters high. > > I raised your model to 2 meters, that reduced the R to about 20 Ohms. Raising it > to 3 meters lowers it to 18 Ohms. > > How did you calculate the H of the loading coils? Is that easy to edit? It would > seem that these values are closer. > > Dan > > Frank's Basement 2 wrote: > > Hi Dan, thanks for the interesting info. You did not specify dimensions, > > but from your comments it appears you are using a vertical about 23 ft high. > > Such a monopole would have a 3.5 ohm input impedance when placed above a > > perfectly conducting ground, and gain about +4.5 dBi. Adding a center > > loading coil raises the input impedance to 11.5 ohms, and gain +2.6 dBi. > > Base loading provides an input impedance of 5.5 ohms with almost the same > > gain as center loading (Q = 400). Adding ten, 6ft radials, at 3" above an > > average ground, the input impedance increases to 40 ohms, and gain -6.3 dBi. > > > > Adding lumped element loading coils, (75 uH, Q = 400) in each radial > > (antenna base end) drops the input impedance to 37 ohms, and gain -6.4 dBi. > > Don't know why this does not agree with Reg's program. Probably I made some > > fundamental error with the NEC model. Included the code below, so you may > > see an error I missed. > > > > 73, > > > > Frank > > > > CM 75 m Vertical 23 ft high > > CE > > GW 1 64 0 0 23 0 0 0.25 0.0026706 > > GW 2 12 0 0 0.25 6 0 0.25 0.0026706 > > GM 1 9 0 0 36 0 0 0 002.002 > > GS 0 0 .3048 > > GE 1 > > GN 2 0 0 0 13.0000 0.0050 > > EX 0 1 64 0 1.00000 0.00000 > > LD 5 1 1 184 5.8001E7 > > LD 4 1 33 33 4 1600 > > LD 4 2 1 1 4 1750 > > LD 4 3 1 1 4 1750 > > LD 4 4 1 1 4 1750 > > LD 4 5 1 1 4 1750 > > LD 4 6 1 1 4 1750 > > LD 4 7 1 1 4 1750 > > LD 4 8 1 1 4 1750 > > LD 4 9 1 1 4 1750 > > LD 4 10 1 1 4 1750 > > LD 4 11 1 1 4 1750 > > FR 0 11 0 0 3.5 0.05 > > RP 0 181 1 1000 -90 0 1.00000 1.00000 > > EN > > > > > > > > > > > >>Frank, > >> > >>Good morning. Let me start at the beginning. I have a loaded vertical on > > > > 75 > > > >>meters. The combination of the antenna and ground measure about 40 Ohms at > > > > the > > > >>antenna. The models all show such an antenna over a perfect ground should > > > > have a > > > >>radiation resistance of between 3 and 4 Ohms. That says the antenna system > > > > is > > > >>less the 10% efficient. > >> > >>This then is a journey to reduce ground resistance. Attempts to add > > > > radials and > > > >>wire mesh to the ground have had very little if no effect. This leads to > > > > Reg's > > > >>c_poise model. It predicts a coil in the range of 60 uH to 90 uH tuned to > > > > a 2 > > > >>meter by 18 mm 'wire' will have a total resistance in the 2 to 4 Ohms > > > > range. > > > >>Together this should result is a 8 Ohm system. The ratio can be directly > >>inferred as an performance improvement of 5 to 1 or 7 db. This is worth > > > > some > > > >>effort. > >> > >>To answer your question the first step will be one coil and one radial. > > > > The > > > >>objective is the get the antenna system close to 10 Ohms. From there I > > > > will > > > >>experiment with adding radials and coils. I am not sure what to expect. > >> > >>Thanks - Dan > >> > >> > >> > >> > >> > >>Frank wrote: > >> > >>>Not sure I understand what is going on Dan. Are you planning on loading > >>>each radial element? > >>> > >>>Frank > >>> > >>> > >>>"dansawyeror" wrote in message > >>>news:43F79966.3070004@comcast.net... > >>> > >>> > >>>>These results were from Reg's c_poise program. The band is 75 meters and > >>>>the coils were about 70 uH. The coils were a relatively large diameter, > > > > on > > > >>>>the order of a meter. The wire lengths were about 20 meters. By varying > >>>>the length the coil, the coil wire may be varies from 1mm to 12mm. > >>>> > >>>>Richard Clark wrote: > >>>> > >>>> > >>>>>On Sat, 18 Feb 2006 08:20:38 -0800, dansawyeror > >>>>> wrote: > >>>>> > >>>>> > >>>>> > >>>>> > >>>>>>The devil is in the details. Modeling shows large coils with 1 mm wire > >>>>>>have a Q in the range of a few hundred. On the other hand a coil with > > > > 12 > > > >>>>>>mm tubing has a Q of about 2000. The R of the 1 mm coil is about 6 > > > > Ohms > > > >>>>>>while the 12 mm coil is on the order of 1 Ohm. > >>>>>> > >>>>>>Given these model results it says there is a significant difference > >>>>>>between 1 mm and 12 mm coils. > >>>>> > >>>>> > >>>>>Hi Dan, > >>>>> > >>>>>In the details, indeed. What is the LENGTH of wire in this 6 Ohm > >>>>>resistor? What is the LENGTH > >>>>>of wire in this 1 Ohm resistor? How many turns are in these "large > >>>>>coils?" What is their diameter? What is their solenoid length? > >>>>> > >>>>>Without these details, there is nothing said that is significant. > >>>>> > >>>>>73's > >>>>>Richard Clark, KB7QHC > >>> > >>> > >>> > > > > Article: 221753 of rec.radio.amateur.antenna From: stananger Subject: Re: Under Eave Antenna References: <43F79B1F.86148B6A@sympatico.ca> <5F1Kf.443$F56.6@newsread3.news.atl.earthlink.net> Message-ID: Date: Mon, 20 Feb 2006 16:27:24 GMT chuck wrote: > If the soffits are not metal, they will probably be dry and just about > anything will do for an insulator/standoff. > >When you said "eaves", some of us assumed you meant under the lowest > edge of the roof. Technically, eaves are the under part of a roof that > hangs over a wall. So the overhangs at the ends of a gable roof are also > called eaves. An inverted vee at one of the ends, fed in the center, > would be something to consider seriously if you have a gable roof. The > center would be perhaps 18 feet above ground. > > On the other hand, if you have a hip roof, then a wire under the eaves > will be entirely horizontal and approximately eight feet high. Such an > antenna will exhibit a near-vertical radiation pattern and it will not > be much of a performer for DX on the HF bands. > > Good luck > > Chuck > > > > > Reg Edwards wrote: >> Just hang up some wire and see what happens. >> >> I make no predictions but you will probably be pleased with results. >> ---- >> Reg. >> >> Everything is wood When you said "eaves", some of us assumed you meant under the lowest > edge of the roof. Technically, eaves are the under part of a roof that > hangs over a wall. So the overhangs at the ends of a gable roof are also > called eaves. An inverted vee at one of the ends, fed in the center, > would be something to consider seriously if you have a gable roof. The > center would be perhaps 18 feet above ground. its going to be a loop and the location you describe is accurate I just wanted to know what the best way to hang this wire from the eave is. Article: 221754 of rec.radio.amateur.antenna From: "Frank's Basement 2" References: <1140274674.116569.208960@g47g2000cwa.googlegroups.com> <43F74956.2060207@comcast.net> <43F79966.3070004@comcast.net> <43F8C006.7030806@comcast.net> <43F95307.5020601@comcast.net> Subject: Re: using coax shield to create a loading coil ? Message-ID: Date: Mon, 20 Feb 2006 16:39:37 GMT Dan, The lumped inductance of 4 +j1750 comes from your previous comment about the inductance range from 60 - 90 uH. I just chose the mid range value of 75 uH at 3.8 MHz. To be exact 2*PI*f*L = 1791 ohms. The real part of 4 ohms is based on an approximate Q of 400. Incidentaly I am working at another location this morning. The computer is an old 600 MHz machine, with 384 MB of RAM, and Windows ME OS. The NEC code here takes 17 seconds to run. 73, Frank "dansawyeror" wrote in message news:43F95307.5020601@comcast.net... > I see the length is set to 1.8 meters already. A 2 meter elevation minimum is > needed to lower ground effects. > > How is the lumped inductance set of 4 Ohms and 1750 Z? What impedance does that > translate to? How did you calculate this value? Dan > > Frank's Basement 2 wrote: > > Hi Dan, thanks for the interesting info. You did not specify dimensions, > > but from your comments it appears you are using a vertical about 23 ft high. > > Such a monopole would have a 3.5 ohm input impedance when placed above a > > perfectly conducting ground, and gain about +4.5 dBi. Adding a center > > loading coil raises the input impedance to 11.5 ohms, and gain +2.6 dBi. > > Base loading provides an input impedance of 5.5 ohms with almost the same > > gain as center loading (Q = 400). Adding ten, 6ft radials, at 3" above an > > average ground, the input impedance increases to 40 ohms, and gain -6.3 dBi. > > > > Adding lumped element loading coils, (75 uH, Q = 400) in each radial > > (antenna base end) drops the input impedance to 37 ohms, and gain -6.4 dBi. > > Don't know why this does not agree with Reg's program. Probably I made some > > fundamental error with the NEC model. Included the code below, so you may > > see an error I missed. > > > > 73, > > > > Frank > > > > CM 75 m Vertical 23 ft high > > CE > > GW 1 64 0 0 23 0 0 0.25 0.0026706 > > GW 2 12 0 0 0.25 6 0 0.25 0.0026706 > > GM 1 9 0 0 36 0 0 0 002.002 > > GS 0 0 .3048 > > GE 1 > > GN 2 0 0 0 13.0000 0.0050 > > EX 0 1 64 0 1.00000 0.00000 > > LD 5 1 1 184 5.8001E7 > > LD 4 1 33 33 4 1600 > > LD 4 2 1 1 4 1750 > > LD 4 3 1 1 4 1750 > > LD 4 4 1 1 4 1750 > > LD 4 5 1 1 4 1750 > > LD 4 6 1 1 4 1750 > > LD 4 7 1 1 4 1750 > > LD 4 8 1 1 4 1750 > > LD 4 9 1 1 4 1750 > > LD 4 10 1 1 4 1750 > > LD 4 11 1 1 4 1750 > > FR 0 11 0 0 3.5 0.05 > > RP 0 181 1 1000 -90 0 1.00000 1.00000 > > EN > > > > > > > > > > > >>Frank, > >> > >>Good morning. Let me start at the beginning. I have a loaded vertical on > > > > 75 > > > >>meters. The combination of the antenna and ground measure about 40 Ohms at > > > > the > > > >>antenna. The models all show such an antenna over a perfect ground should > > > > have a > > > >>radiation resistance of between 3 and 4 Ohms. That says the antenna system > > > > is > > > >>less the 10% efficient. > >> > >>This then is a journey to reduce ground resistance. Attempts to add > > > > radials and > > > >>wire mesh to the ground have had very little if no effect. This leads to > > > > Reg's > > > >>c_poise model. It predicts a coil in the range of 60 uH to 90 uH tuned to > > > > a 2 > > > >>meter by 18 mm 'wire' will have a total resistance in the 2 to 4 Ohms > > > > range. > > > >>Together this should result is a 8 Ohm system. The ratio can be directly > >>inferred as an performance improvement of 5 to 1 or 7 db. This is worth > > > > some > > > >>effort. > >> > >>To answer your question the first step will be one coil and one radial. > > > > The > > > >>objective is the get the antenna system close to 10 Ohms. From there I > > > > will > > > >>experiment with adding radials and coils. I am not sure what to expect. > >> > >>Thanks - Dan > >> > >> > >> > >> > >> > >>Frank wrote: > >> > >>>Not sure I understand what is going on Dan. Are you planning on loading > >>>each radial element? > >>> > >>>Frank > >>> > >>> > >>>"dansawyeror" wrote in message > >>>news:43F79966.3070004@comcast.net... > >>> > >>> > >>>>These results were from Reg's c_poise program. The band is 75 meters and > >>>>the coils were about 70 uH. The coils were a relatively large diameter, > > > > on > > > >>>>the order of a meter. The wire lengths were about 20 meters. By varying > >>>>the length the coil, the coil wire may be varies from 1mm to 12mm. > >>>> > >>>>Richard Clark wrote: > >>>> > >>>> > >>>>>On Sat, 18 Feb 2006 08:20:38 -0800, dansawyeror > >>>>> wrote: > >>>>> > >>>>> > >>>>> > >>>>> > >>>>>>The devil is in the details. Modeling shows large coils with 1 mm wire > >>>>>>have a Q in the range of a few hundred. On the other hand a coil with > > > > 12 > > > >>>>>>mm tubing has a Q of about 2000. The R of the 1 mm coil is about 6 > > > > Ohms > > > >>>>>>while the 12 mm coil is on the order of 1 Ohm. > >>>>>> > >>>>>>Given these model results it says there is a significant difference > >>>>>>between 1 mm and 12 mm coils. > >>>>> > >>>>> > >>>>>Hi Dan, > >>>>> > >>>>>In the details, indeed. What is the LENGTH of wire in this 6 Ohm > >>>>>resistor? What is the LENGTH > >>>>>of wire in this 1 Ohm resistor? How many turns are in these "large > >>>>>coils?" What is their diameter? What is their solenoid length? > >>>>> > >>>>>Without these details, there is nothing said that is significant. > >>>>> > >>>>>73's > >>>>>Richard Clark, KB7QHC > >>> > >>> > >>> > > > > Article: 221755 of rec.radio.amateur.antenna From: Dot Subject: Re: Under Eave Antenna Message-ID: References: <43F79B1F.86148B6A@sympatico.ca> <5F1Kf.443$F56.6@newsread3.news.atl.earthlink.net> Date: Mon, 20 Feb 2006 11:35:07 -0500 On Mon, 20 Feb 2006 16:27:24 GMT, stananger wrote: >Everything is wood >... >I just wanted to know what the best way to hang this wire from the eave is. If everything is wood, you could probably just staple the wire under the eves of your house. Article: 221756 of rec.radio.amateur.antenna From: "johan aeq" References: <1140420029.713791.128680@g47g2000cwa.googlegroups.com> Subject: Re: Low power 5w FM Transmitter antenna Date: Mon, 20 Feb 2006 19:09:28 +0100 Message-ID: a simple receiver antenna will do fine. Just don't use a amplified antenna. With 5Watts a simple 1:4 ferritebalun in the connectionbox will do the coax to foldeddipole match too. schreef in bericht news:1140420029.713791.128680@g47g2000cwa.googlegroups.com... > Hello, > > A friend of mine live in outback NSW and wants to install a 5w FM > Transmitter on his property to transmit music between buildings - 88 - > 108mhz - can anybody suggest an antenna for this purpose - maybe a link > to manufacturer/distributor in Australia? Yes we understand that it is > most probably illegal but think that signal will not drift off > property. > > Thanks in advance. > Article: 221757 of rec.radio.amateur.antenna From: John Ferrell Subject: Re: Smith Chart vs JAVA Message-ID: References: <1pifv1l0gc9ji32ipa3os3gfma0en7nvn5@4ax.com> Date: Mon, 20 Feb 2006 18:22:34 GMT FWIW: Both the web site and the dowloaded Java appear to work properly on Linux SUSE 10 under KDE, Konquer and Firefox. On Mon, 20 Feb 2006 13:27:29 GMT, John Ferrell wrote: >It also fails to run as a download from the XP Home Laptop (also IE >6). John Ferrell W8CCW Article: 221758 of rec.radio.amateur.antenna From: "Frank's Basement 2" References: <1140274674.116569.208960@g47g2000cwa.googlegroups.com> <43F74956.2060207@comcast.net> <43F79966.3070004@comcast.net> <43F8C006.7030806@comcast.net> <43F95307.5020601@comcast.net> Subject: Re: using coax shield to create a loading coil ? Message-ID: Date: Mon, 20 Feb 2006 18:50:23 GMT Dan, here is a preliminary run on a 12 ft monopole model structured as follows: base at 6 ft, 10 x 6ft radials. All #14 AWG. Ground - perfect, frequency 3.8 MHz. Zin = 0.968 - j1847.55 ohms; Efficiency = 87.4 % (structure copper loss); Gain = 4.15 dBi; Take-off angle = 0 deg; Gain at 27 deg elevation (expected TOA with real ground) = +3.09 dBi. I will try successive modifications to approach a practical model. The code I used, modified so it should run in 4nec2, is shown below. 73, Frank CM 75 m Vertical 12 ft high CM base 6 ft up, 10 X 6 ft radials CM copper conductivity CE GW 1 24 0 0 18 0 0 6 0.0026706 GW 2 12 0 0 6 6 0 6 0.0026706 GM 1 9 0 0 36 0 0 0 2 GS 0 0 .3048 GE 1 GN 1 EX 0 1 24 0 1.00000 0.00000 LD 5 1 1 144 5.8001E7 FR 0 11 0 0 3.5 0.05 RP 0 181 1 1000 -90 0 1.00000 1.00000 EN "Frank's Basement 2" wrote in message news:dhmKf.6088$_62.3050@edtnps90... > Dan, > > The lumped inductance of 4 +j1750 comes from your previous comment about the > inductance range from 60 - 90 uH. I just chose the mid range value of 75 uH > at 3.8 MHz. To be exact 2*PI*f*L = 1791 ohms. The real part of 4 ohms is > based on an approximate Q of 400. > > Incidentaly I am working at another location this morning. The computer is > an old 600 MHz machine, with 384 MB of RAM, and Windows ME OS. The NEC code > here takes 17 seconds to run. > > 73, > > Frank > "dansawyeror" wrote in message > news:43F95307.5020601@comcast.net... > > I see the length is set to 1.8 meters already. A 2 meter elevation minimum > is > > needed to lower ground effects. > > > > How is the lumped inductance set of 4 Ohms and 1750 Z? What impedance does > that > > translate to? How did you calculate this value? Dan > > > > Frank's Basement 2 wrote: > > > Hi Dan, thanks for the interesting info. You did not specify > dimensions, > > > but from your comments it appears you are using a vertical about 23 ft > high. > > > Such a monopole would have a 3.5 ohm input impedance when placed above a > > > perfectly conducting ground, and gain about +4.5 dBi. Adding a center > > > loading coil raises the input impedance to 11.5 ohms, and gain +2.6 dBi. > > > Base loading provides an input impedance of 5.5 ohms with almost the > same > > > gain as center loading (Q = 400). Adding ten, 6ft radials, at 3" above > an > > > average ground, the input impedance increases to 40 ohms, and gain -6.3 > dBi. > > > > > > Adding lumped element loading coils, (75 uH, Q = 400) in each radial > > > (antenna base end) drops the input impedance to 37 ohms, and gain -6.4 > dBi. > > > Don't know why this does not agree with Reg's program. Probably I made > some > > > fundamental error with the NEC model. Included the code below, so you > may > > > see an error I missed. > > > > > > 73, > > > > > > Frank > > > > > > CM 75 m Vertical 23 ft high > > > CE > > > GW 1 64 0 0 23 0 0 0.25 0.0026706 > > > GW 2 12 0 0 0.25 6 0 0.25 0.0026706 > > > GM 1 9 0 0 36 0 0 0 002.002 > > > GS 0 0 .3048 > > > GE 1 > > > GN 2 0 0 0 13.0000 0.0050 > > > EX 0 1 64 0 1.00000 0.00000 > > > LD 5 1 1 184 5.8001E7 > > > LD 4 1 33 33 4 1600 > > > LD 4 2 1 1 4 1750 > > > LD 4 3 1 1 4 1750 > > > LD 4 4 1 1 4 1750 > > > LD 4 5 1 1 4 1750 > > > LD 4 6 1 1 4 1750 > > > LD 4 7 1 1 4 1750 > > > LD 4 8 1 1 4 1750 > > > LD 4 9 1 1 4 1750 > > > LD 4 10 1 1 4 1750 > > > LD 4 11 1 1 4 1750 > > > FR 0 11 0 0 3.5 0.05 > > > RP 0 181 1 1000 -90 0 1.00000 1.00000 > > > EN > > > > > > > > > > > > > > > > > >>Frank, > > >> > > >>Good morning. Let me start at the beginning. I have a loaded vertical on > > > > > > 75 > > > > > >>meters. The combination of the antenna and ground measure about 40 Ohms > at > > > > > > the > > > > > >>antenna. The models all show such an antenna over a perfect ground > should > > > > > > have a > > > > > >>radiation resistance of between 3 and 4 Ohms. That says the antenna > system > > > > > > is > > > > > >>less the 10% efficient. > > >> > > >>This then is a journey to reduce ground resistance. Attempts to add > > > > > > radials and > > > > > >>wire mesh to the ground have had very little if no effect. This leads to > > > > > > Reg's > > > > > >>c_poise model. It predicts a coil in the range of 60 uH to 90 uH tuned > to > > > > > > a 2 > > > > > >>meter by 18 mm 'wire' will have a total resistance in the 2 to 4 Ohms > > > > > > range. > > > > > >>Together this should result is a 8 Ohm system. The ratio can be directly > > >>inferred as an performance improvement of 5 to 1 or 7 db. This is worth > > > > > > some > > > > > >>effort. > > >> > > >>To answer your question the first step will be one coil and one radial. > > > > > > The > > > > > >>objective is the get the antenna system close to 10 Ohms. From there I > > > > > > will > > > > > >>experiment with adding radials and coils. I am not sure what to expect. > > >> > > >>Thanks - Dan > > >> > > >> > > >> > > >> > > >> > > >>Frank wrote: > > >> > > >>>Not sure I understand what is going on Dan. Are you planning on > loading > > >>>each radial element? > > >>> > > >>>Frank > > >>> > > >>> > > >>>"dansawyeror" wrote in message > > >>>news:43F79966.3070004@comcast.net... > > >>> > > >>> > > >>>>These results were from Reg's c_poise program. The band is 75 meters > and > > >>>>the coils were about 70 uH. The coils were a relatively large > diameter, > > > > > > on > > > > > >>>>the order of a meter. The wire lengths were about 20 meters. By > varying > > >>>>the length the coil, the coil wire may be varies from 1mm to 12mm. > > >>>> > > >>>>Richard Clark wrote: > > >>>> > > >>>> > > >>>>>On Sat, 18 Feb 2006 08:20:38 -0800, dansawyeror > > >>>>> wrote: > > >>>>> > > >>>>> > > >>>>> > > >>>>> > > >>>>>>The devil is in the details. Modeling shows large coils with 1 mm > wire > > >>>>>>have a Q in the range of a few hundred. On the other hand a coil > with > > > > > > 12 > > > > > >>>>>>mm tubing has a Q of about 2000. The R of the 1 mm coil is about 6 > > > > > > Ohms > > > > > >>>>>>while the 12 mm coil is on the order of 1 Ohm. > > >>>>>> > > >>>>>>Given these model results it says there is a significant difference > > >>>>>>between 1 mm and 12 mm coils. > > >>>>> > > >>>>> > > >>>>>Hi Dan, > > >>>>> > > >>>>>In the details, indeed. What is the LENGTH of wire in this 6 Ohm > > >>>>>resistor? What is the LENGTH > > >>>>>of wire in this 1 Ohm resistor? How many turns are in these "large > > >>>>>coils?" What is their diameter? What is their solenoid length? > > >>>>> > > >>>>>Without these details, there is nothing said that is significant. > > >>>>> > > >>>>>73's > > >>>>>Richard Clark, KB7QHC > > >>> > > >>> > > >>> > > > > > > > > Article: 221759 of rec.radio.amateur.antenna From: stananger Subject: Re: Under Eave Antenna References: <43F79B1F.86148B6A@sympatico.ca> <5F1Kf.443$F56.6@newsread3.news.atl.earthlink.net> Message-ID: Date: Mon, 20 Feb 2006 19:27:30 GMT Dot wrote: > On Mon, 20 Feb 2006 16:27:24 GMT, stananger > wrote: > >>Everything is wood >>... >>I just wanted to know what the best way to hang this wire from the eave >>is. > > > If everything is wood, you could probably just staple the wire under the > eves of your house. But staples are metal, which might compress the wire against the wood and damage the wire. Not sure if the staples being metal would effect anything but it I was hoping someone had some experience with this kind of setup. I was thinking of stapling a black UV resistant cable tie every 10-15 ft and running the wire thru the loop made by the cable tie. Actually a bad idea I think. Someone did mention the screw in type tv cable standoffs. Thats a possibility but I guess I am looking for someone who has actually done this to see what they had done and what problems they had encountered. Another poster also mentioned it would be a poor DX antenna, maybe, as my house sits on sloping ground and is post and pier the eaves are over 25' on 1/2 of the house. This could be a decent antenna for maybe 15 & 10 meters. But in my original post the idea was to be used as a receiving antenna maybe for transmitting on 40 & 75 locally. One point I do want to make again - the other half wants me to make sure its as eye pleasing as possible, which means it cant be easy to see. When I first thought about doing this I never realized it actually required as much time to come up with a solution as it has. Simple project? You and I would have thought so. Article: 221760 of rec.radio.amateur.antenna From: Bob Bob Subject: Re: Low power 5w FM Transmitter antenna References: <1140420029.713791.128680@g47g2000cwa.googlegroups.com> Message-ID: Date: Mon, 20 Feb 2006 13:49:37 -0600 Dunno if I'd go the ferrite path. If you dont know the material it may just end up saturating and being radiated as heat! I'd suggest a frequency dependent match like a 4:1 coaxial balun if you want to use a folded dipole. Thats just a 1/2 wave length of coax at the right freq allowing for velocity factor. Lots of places to search what that looks like on the web. try; http://n-lemma.com/calcs/dipole/balun.htm You could use a ferrite balun especially if you are looking for broadband use. Take care with material selection and wire turns though. Cheers Bob johan aeq wrote: > a simple receiver antenna will do fine. > Just don't use a amplified antenna. > With 5Watts a simple 1:4 ferritebalun in the connectionbox will do the coax > to foldeddipole match too. Article: 221761 of rec.radio.amateur.antenna From: Dot Subject: Re: Under Eave Antenna Message-ID: References: <43F79B1F.86148B6A@sympatico.ca> <5F1Kf.443$F56.6@newsread3.news.atl.earthlink.net> Date: Mon, 20 Feb 2006 15:36:19 -0500 On Mon, 20 Feb 2006 19:27:30 GMT, stananger wrote: >But staples are metal, which might compress the wire against the wood and >damage the wire. Try these... http://1shop2.com/ace_electrical/GB-Coaxial-Staple.html >Not sure if the staples being metal would effect anything Naaa not if you don't get carried away. >One point I do want to make again - the other half wants me to make sure its >as eye pleasing as possible, which means it cant be easy to see. Hiding antennas is something of a specialty of mine. >When I first thought about doing this I never realized it actually required >as much time to come up with a solution as it has. >Simple project? You and I would have thought so. ANY project worth doing is worth doing right. Article: 221762 of rec.radio.amateur.antenna From: "Bill Berris" References: <4a7Kf.49300$dW3.14954@newssvr21.news.prodigy.com> <2H9Kf.144$vd2.11@fed1read04> Subject: Re: 2m/440 antenna Q's Message-ID: Date: Mon, 20 Feb 2006 21:19:20 GMT "Sal M. Onella" wrote in message news:2H9Kf.144$vd2.11@fed1read04... > > "Bill Berris" wrote in message Thanks for the info! I think that a J-Pole is in my future... :-) -- Bill Berris, KF6CNP Salida, CA ------------------- Article: 221763 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Under Eave Antenna References: <43F79B1F.86148B6A@sympatico.ca> <5F1Kf.443$F56.6@newsread3.news.atl.earthlink.net> Message-ID: <9zqKf.59268$PL5.49637@newssvr11.news.prodigy.com> Date: Mon, 20 Feb 2006 21:31:49 GMT stananger wrote: > When I first thought about doing this I never realized it actually required > as much time to come up with a solution as it has. If you keep thinking and talking about it until you have a perfect solution, it will never get done. :-) -- 73, Cecil http://www.qsl.net/w5dxp Article: 221764 of rec.radio.amateur.antenna From: "Frank" References: <1140274674.116569.208960@g47g2000cwa.googlegroups.com> <43F74956.2060207@comcast.net> <43F79966.3070004@comcast.net> <43F8C006.7030806@comcast.net> <43F9471A.4090904@comcast.net> <43FA2154.1060305@comcast.net> Subject: Re: using coax shield to create a loading coil ? Message-ID: Date: Mon, 20 Feb 2006 22:01:57 GMT Hi Dan, I tried your program, it runs fine, and I get identical results. I also learned a couple of things from your code: Setting "GE" = 0 implies no ground plane present (I would normally set it to "1"), and my "Nec Vu" function shows the antenna with no ground plane. Running the program, however, returns the correct result with an average ground. I also ran the program with no radial loading (code below), and the gain increased marginally. It seems loading the radials does not help much. Frank CM 75 m Vertical 16 ft high CE GW 1 11 0 0 7.5342 0 0 2.6 8.13999e-4 GW 2 12 0 0 2.6 1.8288 0 2.6 8.13999e-4 GW 3 12 0 0 2.6 1.47953028 1.07494167 2.6 8.13999e-4 GW 4 12 0 0 2.6 0.56513028 1.73929216 2.6 8.13999e-4 GW 5 12 0 0 2.6 -0.5651303 1.73929216 2.6 8.13999e-4 GW 6 12 0 0 2.6 -1.4795303 1.07494167 2.6 8.13999e-4 GW 7 12 0 0 2.6 -1.8288 2.2396e-16 2.6 8.13999e-4 GW 8 12 0 0 2.6 -1.4795303 -1.0749417 2.6 8.13999e-4 GW 9 12 0 0 2.6 -0.5651303 -1.7392922 2.6 8.13999e-4 GW 10 12 0 0 2.6 0.56513028 -1.7392922 2.6 8.13999e-4 GW 11 12 0 0 2.6 1.47953028 -1.0749417 2.6 8.13999e-4 GE 1 GN 2 0 0 0 13.0000 0.0050 LD 4 1 7 7 3 2100 LD 5 1 1 107 5.8001E7 EX 0 1 11 00 1 0 FR 0 11 0 0 3.5 0.05 RP 0 181 1 1000 -90 90 1.00000 1.00000 EN "dansawyeror" wrote in message news:43FA2154.1060305@comcast.net... > Frank, > > Good morning. I had a few minutes and created the following model. It is > shortened and the number of segments in the vertical is increased. I also > set the inductors to 3 Ohms. (That may be optimistic for the antenna, > Reg's program predicts 2 Ohms is achievable for larger coils on the > radials.) (Sorry for the long numbers.) This shows a resonance at 3.9 MHz > and 9.9 Ohms. > > 4nec2 did not like the GM card, I did not remove it. > > Dan > > CM 75 m Vertical 16 ft high > CE > GW 1 11 0 0 7.5342 0 0 2.6 > 8.13999e-4 > GW 2 12 0 0 2.6 1.8288 0 2.6 > 8.13999e-4 > GW 3 12 0 0 2.6 1.47953028 1.07494167 > 2.6 8.13999e-4 > GW 4 12 0 0 2.6 0.56513028 1.73929216 > 2.6 8.13999e-4 > GW 5 12 0 0 2.6 -0.5651303 1.73929216 > 2.6 8.13999e-4 > GW 6 12 0 0 2.6 -1.4795303 1.07494167 > 2.6 8.13999e-4 > GW 7 12 0 0 2.6 -1.8288 2.2396e-16 > 2.6 8.13999e-4 > GW 8 12 0 0 2.6 -1.4795303 -1.0749417 > 2.6 8.13999e-4 > GW 9 12 0 0 2.6 -0.5651303 -1.7392922 > 2.6 8.13999e-4 > GW 10 12 0 0 2.6 0.56513028 -1.7392922 > 2.6 8.13999e-4 > GW 11 12 0 0 2.6 1.47953028 -1.0749417 > 2.6 8.13999e-4 > GE 0 > LD 5 1 0 0 58001000 0 > LD 4 1 7 7 3 2100 > LD 4 2 1 1 3 2000 > LD 4 3 1 1 3 2000 > LD 4 4 1 1 3 2000 > LD 4 5 1 1 3 2000 > LD 4 6 1 1 3 2000 > LD 4 7 1 1 3 2000 > LD 4 8 1 1 3 2000 > LD 4 9 1 1 3 2000 > LD 4 10 1 1 3 2000 > LD 4 11 1 1 3 2000 > EX 0 1 11 0 1 0 > GN 2 0 0 0 13 5.e-3 > FR 0 1 0 0 3.5 0 > EN > > > > Frank wrote: >> Dan, >> >> I find antenna problems very interesting, so do not mind spending time on >> running models. >> >> The radials were based on your comments in an earlier post about "2 meter >> radials". You have provided me with a lot of information in subsequent >> posts, so will use that info to try and construct a more realistic model. >> I still have a couple of questions though: how many radials are you >> using, and where do you position the radial loading coils? >> >> You are correct about the "GM" problem, and I forgot it produced an error >> in 4nec2. The last "ITS" field should be an integer. I have not >> completely confirmed it with 4nec2, but the ITS field refers to the tag >> to be replicated -- in this case tag 2. GM generates 9 tags rotated by >> 36 degrees, and saves a ton of GW cards. >> >> I cannot understand why your simulation takes 5 minutes since there are >> only 184 segments, and 11 frequencies. I just checked and it takes only >> 3.9 seconds with my NEC2 program, or 4nec2. Anyway my model will take a >> lot of revision to replicate your actual antenna. May get a chance to >> look at it later tonight. >> >> 73, >> >> Frank >> >> >> "dansawyeror" wrote in message >> news:43F9471A.4090904@comcast.net... >> >>>Frank, >>> >>>Thanks for the model. I did not expect you to model this or I would have >>>been more specific. The antenna is about 14 feet. The coil is about 4 >>>feet from the base. >>> >>>Now the radials: Did you base the radial from Reg's model? Try 3.97 MHz, >>>1 meter above ground, 3 meter radials, and a 60mm long by 300 mm dia 66.7 >>>uH loading coil. These grounds have to be tuned as well. >>> >>>I am using 4nec2 and am getting errors from the GM card. Wasn't there an >>>issue with these being a decimal instead of an integer? >>> >>>BTW - The simulation on my laptop takes over 5 minutes to run. >>> >>>Dan >>> >>>Frank's Basement 2 wrote: >>> >>>>Hi Dan, thanks for the interesting info. You did not specify >>>>dimensions, >>>>but from your comments it appears you are using a vertical about 23 ft >>>>high. >>>>Such a monopole would have a 3.5 ohm input impedance when placed above a >>>>perfectly conducting ground, and gain about +4.5 dBi. Adding a center >>>>loading coil raises the input impedance to 11.5 ohms, and gain +2.6 dBi. >>>>Base loading provides an input impedance of 5.5 ohms with almost the >>>>same >>>>gain as center loading (Q = 400). Adding ten, 6ft radials, at 3" above >>>>an >>>>average ground, the input impedance increases to 40 ohms, and gain -6.3 >>>>dBi. >>>> >>>>Adding lumped element loading coils, (75 uH, Q = 400) in each radial >>>>(antenna base end) drops the input impedance to 37 ohms, and gain -6.4 >>>>dBi. >>>>Don't know why this does not agree with Reg's program. Probably I made >>>>some >>>>fundamental error with the NEC model. Included the code below, so you >>>>may >>>>see an error I missed. >>>> >>>>73, >>>> >>>>Frank >>>> >>>>CM 75 m Vertical 23 ft high >>>>CE >>>>GW 1 64 0 0 23 0 0 0.25 0.0026706 >>>>GW 2 12 0 0 0.25 6 0 0.25 0.0026706 >>>>GM 1 9 0 0 36 0 0 0 002.002 >>>>GS 0 0 .3048 >>>>GE 1 >>>>GN 2 0 0 0 13.0000 0.0050 >>>>EX 0 1 64 0 1.00000 0.00000 >>>>LD 5 1 1 184 5.8001E7 >>>>LD 4 1 33 33 4 1600 >>>>LD 4 2 1 1 4 1750 >>>>LD 4 3 1 1 4 1750 >>>>LD 4 4 1 1 4 1750 >>>>LD 4 5 1 1 4 1750 >>>>LD 4 6 1 1 4 1750 >>>>LD 4 7 1 1 4 1750 >>>>LD 4 8 1 1 4 1750 >>>>LD 4 9 1 1 4 1750 >>>>LD 4 10 1 1 4 1750 >>>>LD 4 11 1 1 4 1750 >>>>FR 0 11 0 0 3.5 0.05 >>>>RP 0 181 1 1000 -90 0 1.00000 1.00000 >>>>EN >>>> >>>> >>>> >>>> >>>> >>>> >>>>>Frank, >>>>> >>>>>Good morning. Let me start at the beginning. I have a loaded vertical >>>>>on >>>> >>>>75 >>>> >>>> >>>>>meters. The combination of the antenna and ground measure about 40 Ohms >>>>>at >>>> >>>>the >>>> >>>> >>>>>antenna. The models all show such an antenna over a perfect ground >>>>>should >>>> >>>>have a >>>> >>>> >>>>>radiation resistance of between 3 and 4 Ohms. That says the antenna >>>>>system >>>> >>>>is >>>> >>>> >>>>>less the 10% efficient. >>>>> >>>>>This then is a journey to reduce ground resistance. Attempts to add >>>> >>>>radials and >>>> >>>> >>>>>wire mesh to the ground have had very little if no effect. This leads >>>>>to >>>> >>>>Reg's >>>> >>>> >>>>>c_poise model. It predicts a coil in the range of 60 uH to 90 uH tuned >>>>>to >>>> >>>>a 2 >>>> >>>> >>>>>meter by 18 mm 'wire' will have a total resistance in the 2 to 4 Ohms >>>> >>>>range. >>>> >>>> >>>>>Together this should result is a 8 Ohm system. The ratio can be >>>>>directly >>>>>inferred as an performance improvement of 5 to 1 or 7 db. This is worth >>>> >>>>some >>>> >>>> >>>>>effort. >>>>> >>>>>To answer your question the first step will be one coil and one radial. >>>> >>>>The >>>> >>>> >>>>>objective is the get the antenna system close to 10 Ohms. From there I >>>> >>>>will >>>> >>>> >>>>>experiment with adding radials and coils. I am not sure what to expect. >>>>> >>>>>Thanks - Dan >>>>> >>>>> >>>>> >>>>> >>>>> >>>>>Frank wrote: >>>>> >>>>> >>>>>>Not sure I understand what is going on Dan. Are you planning on >>>>>>loading >>>>>>each radial element? >>>>>> >>>>>>Frank >>>>>> >>>>>> >>>>>>"dansawyeror" wrote in message >>>>>>news:43F79966.3070004@comcast.net... >>>>>> >>>>>> >>>>>> >>>>>>>These results were from Reg's c_poise program. The band is 75 meters >>>>>>>and >>>>>>>the coils were about 70 uH. The coils were a relatively large >>>>>>>diameter, >>>> >>>>on >>>> >>>> >>>>>>>the order of a meter. The wire lengths were about 20 meters. By >>>>>>>varying >>>>>>>the length the coil, the coil wire may be varies from 1mm to 12mm. >>>>>>> >>>>>>>Richard Clark wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>>>On Sat, 18 Feb 2006 08:20:38 -0800, dansawyeror >>>>>>>> wrote: >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>>>The devil is in the details. Modeling shows large coils with 1 mm >>>>>>>>>wire >>>>>>>>>have a Q in the range of a few hundred. On the other hand a coil >>>>>>>>>with >>>> >>>>12 >>>> >>>> >>>>>>>>>mm tubing has a Q of about 2000. The R of the 1 mm coil is about 6 >>>> >>>>Ohms >>>> >>>> >>>>>>>>>while the 12 mm coil is on the order of 1 Ohm. >>>>>>>>> >>>>>>>>>Given these model results it says there is a significant difference >>>>>>>>>between 1 mm and 12 mm coils. >>>>>>>> >>>>>>>> >>>>>>>>Hi Dan, >>>>>>>> >>>>>>>>In the details, indeed. What is the LENGTH of wire in this 6 Ohm >>>>>>>>resistor? What is the LENGTH >>>>>>>>of wire in this 1 Ohm resistor? How many turns are in these "large >>>>>>>>coils?" What is their diameter? What is their solenoid length? >>>>>>>> >>>>>>>>Without these details, there is nothing said that is significant. >>>>>>>> >>>>>>>>73's >>>>>>>>Richard Clark, KB7QHC >>>>>> >>>>>> >>>>>> >> Article: 221765 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: using coax shield to create a loading coil ? Date: Mon, 20 Feb 2006 15:29:00 -0800 Message-ID: <11vkk5vrumlac0a@corp.supernews.com> References: <11vc4ntcub1k91@corp.supernews.com> <1140207382.882131.11500@z14g2000cwz.googlegroups.com> <11vctsaacbdfa57@corp.supernews.com> <1140228740.616862.294460@g14g2000cwa.googlegroups.com> <11vd24h21qefea@corp.supernews.com> <1140266886.722102.279930@z14g2000cwz.googlegroups.com> <11vecbaciouhcda@corp.supernews.com> Reg Edwards wrote: > > Roy, you seem to have forgotten proximity effect. >. . . Forgotten? I just didn't see what relevance it had on the difference in Q between an inductor made from a braided coax shield and one made from solid tubing. And I can't see from your posting anything which adds to that discussion. But maybe I'm missing something? Roy Lewallen, W7EL Article: 221766 of rec.radio.amateur.antenna From: "Michael" Subject: New yahoo group. Receive VMS from Inmarsat and decode the signals. Message-ID: <6AsKf.5692$x5.2815@news.get2net.dk> Date: Tue, 21 Feb 2006 18:36:36 +0100 My name is Michael. I'm educated as electronic mechanic. I started a project with the goal to receive and decode the VMS signals from Inmarsat. VMS system is manly used on fishing vessels. On the ship there is a box with a gps and satellite transceiver. The position information is send each hour, to a land earth station, were it is distributed to the different authorities. I hope that many of you will help and contribute to get this working, because I don't have all the skills my self. First I started to ask people in different news group about the subject. But I now realized that it will be a bigger task. So I have made a Yahoo group to get this thing going. I have in this group posted the information I have gathered until now. If you think you maybe can contribute to the project then, or is interested in this as well, then please join at http://groups.yahoo.com/group/vms_group Cheers Michael Article: 221767 of rec.radio.amateur.antenna From: "SignalFerret" References: Subject: Re: Aux Antenna for Wlakman FM radio? Message-ID: Date: Tue, 21 Feb 2006 00:08:04 GMT I wouldn't over think it too much. Try just a floppy wire 18 inches or so, and see what noise it picks up? You're bigger problem is those radios aren't designed to pick up distant stations, so outside of a large metro area you might not get any reception, or worse a signal that constantly fades in and out. Try the simplest solution first, then start adding pieces. Robert N3LGC "Ken C" wrote in message news:sq8ev1ledr52hi0hhsa25v9lhbkav95r57@4ax.com... > On Fri, 17 Feb 2006 04:27:04 GMT, "SignalFerret" > wrote: > >>The shield on the headphone cable is used as the antenna for such devices. >>As for matching, how good of a match can a headphone cable be? Inside >>most >>radios the connection is a single cap, in the pF range, between the jack >>and >>the RF front end. > > Hmm. Well, the shield on the shielded stereo cable between the player > and the helmet sound module might pick up some interference from the > motorcycle's electrics. What components would you suggest that I > install on that cable to filter that out? Basically, I would want to > filter out everything that is not audio frequency (20 Hz - 20 kHz) or > between 88-108 MHz. > > The player headphones have a main cable that is 29" long before > splitting to each headphobne. This is 1/4 wave for FM BCB. I could, > as you suggest, splice in a 29" wire at the player end of the cable. > > Ken KC2JDY > Article: 221768 of rec.radio.amateur.antenna From: "amdx" References: <1ZGdnWnvTqTP42reRVn-rw@adelphia.com> <87SdnUlqsvC2MmXenZ2dnUVZ_tudnZ2d@adelphia.com> Subject: Re: Accuracy of Q meters Date: Mon, 20 Feb 2006 18:20:01 -0600 Message-ID: <3c19$43fa5cb4$45011502$21298@KNOLOGY.NET> "John Popelish" wrote in message news:87SdnUlqsvC2MmXenZ2dnUVZ_tudnZ2d@adelphia.com... > Reg Edwards wrote: > > John, thanks for describing your detailed and recent interesting > > experience and your thoughts on the subject. > > > > However, once again the question is raised - how does one calibrate a > > Q meter? Rhetorically, is calibration traceable to National or > > International Standards? > > Q is the ratio of two values (and several different pairs of values > can be used to arrive at the same end result). For a coil, one ratio > that produces a value of Q is the peak energy stored during an AC > cycle to the total energy dissipated during a cycle. If you can > measure those two quantities, separately, you can calculate Q. But it > is often much easier to work with a resonant tank and use a capacitor > that is known to have a much higher Q than the coil being tested, so > that you can assume that all the losses are in the coil. Then the > tank circuit Q is the coil Q. This is the bases of the Boonton 160A > and also the signal generator, voltmeter method I have been using. > > > So much depends on the Q quality of the meter itself. > > The meter quality has to be higher than the Q of the device being > measured, of a compensation has to be made for the meter losses. For > instance, with the signal generator voltmeter method, I have > calculated the losses in the two 10X probes, to prove to myself that > the errors they cause are not significant up to the highest Q values I > measured, this way. I would have had to measure a Q near 1000 before > they would have altered a significant digit of the measurement. But I > did convince myself that energy absorption outside the coil in > surrounding objects is significant, since shifting my position in my > chair did change the measurement. > > > Meter > > manufacturers are unable to state degrees of accuracy at various > > frequencies and actual values of Q. Nobody knows what the actual > > value actually is! Least of all the user! > > Boonton originally sold Q standard coils (inductors with known Q) to > be used to check the accuracy of the Q meters. I don't know how those > coils calibration got back to basic measurements traced to the Bureau > of standards. > > > > Fortunately, the exact value of Q of a coil is never required. It is > > used only to provide coarse estimates of other quantities. And there > > are usually other means of finding the other quantities. They can be > > estimated by calculating from values which CAN be measured or > > estimated. > > I agree. Usually, proving that a given device has at least a certain > Q is enough, or tests made on various devices by the same method can > show which ones have higher Q than others. This is what I am doing > with the measurements. > > > So Q meters provide support and back up for experimenters who have > > other means of finding the answers they are looking for. By itself a > > measured value of Q is inaccurate and of no use. What matters is what > > can be derived or guessed from it. > > Q is a way to measure losses. If losses are important to the > application, Q is one way to get information that is useful. An > infrared thermal imager may be another. > > > It is merely an intermediate variable in a chain of deductions or > > calculations. Above Q equal to a few hundreds it is anybody's guess. > > > > In some ways it is similar to an SWR measurement on a line which isn't > > there. > > ---- > > Reg. > > > > Article: 221769 of rec.radio.amateur.antenna From: "amdx" References: <1ZGdnWnvTqTP42reRVn-rw@adelphia.com> <87SdnUlqsvC2MmXenZ2dnUVZ_tudnZ2d@adelphia.com> Subject: Re: Accuracy of Q meters Date: Mon, 20 Feb 2006 18:27:44 -0600 Message-ID: <1e5bc$43fa5e83$45011502$21708@KNOLOGY.NET> > > The meter quality has to be higher than the Q of the device being > measured, of a compensation has to be made for the meter losses. For > instance, with the signal generator voltmeter method, I have > calculated the losses in the two 10X probes, to prove to myself that > the errors they cause are not significant up to the highest Q values I > measured, this way. I would have had to measure a Q near 1000 before > they would have altered a significant digit of the measurement. But I > did convince myself that energy absorption outside the coil in > surrounding objects is significant, since shifting my position in my > chair did change the measurement. > > > It has been a while since I measured the 3db points of a inductor, but I think the probe did load the coil. I recall putting a 1meg resistor in series with the probe to help isolate the probe capacitance from the inductor. Mike Article: 221770 of rec.radio.amateur.antenna From: Bob Miller Subject: Re: Under Eave Antenna Message-ID: References: <43F79B1F.86148B6A@sympatico.ca> <5F1Kf.443$F56.6@newsread3.news.atl.earthlink.net> Date: Tue, 21 Feb 2006 01:16:29 GMT On Mon, 20 Feb 2006 19:27:30 GMT, stananger wrote: >Simple project? You and I would have thought so. Hang it up there, sloppily, just to see if it works. Otherwise, you may go to a lot of refinement and trouble for naught. bob k5qwg Article: 221771 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Fiberglass roof on FJ-40 Date: Mon, 20 Feb 2006 17:41:04 -0800 Message-ID: <11vkrtkc63fde98@corp.supernews.com> References: On mine, I mounted a telescoping BC band replacement antenna at the top of the metal body piece just behind the door and collapsed it down to about a quarter wave on 2 meters. Although you could probably fiddle the antenna length to get a fair match, I built a little highpass T network out of an inductor on a small powdered iron core and a couple of trimmer capacitors to do the matching. The pattern is probably pretty skewed, but it's adequate to reach the local repeaters. You could mount a dual band antenna at that same spot with some sort of right angle mount. A half wave antenna at the top of the roof should work ok, but even with a half wave antenna, there's a small amount of return current that has to go somewhere. If I were willing to punch a hole in the top (which I'm not -- have you seen what a replacement top costs?), I'd do something like put a small ground plane inside the car against the top. This might be a reasonable application for a through-glass antenna -- through one of the windows, that is, although it might be interesting to see how one would work as a through-the-top antenna if you could rotate it to be vertical. But having spent quite a few hours studying various patents for their design, it looks like some might work much better than others. Roy Lewallen, W7EL Harbin wrote: > Howdy Y'all: > > I have a fiberglass roof on my Landcruiser, and I was wondering if I can use a halfwave roof mounted antenna? > For some reason, I think since the halfwave is end loaded, that it will not work on my fiberglass roof, and that > it uses a steel roof as part of the match. Am I wrong here? The only other thing I can think of is some kind of > stainless steel J pole on a mount coming off the back. And what about a dual band that will work on fiberglass? > Anybody work with this problem before? > > SeeYaa:) Harbin > > Article: 221772 of rec.radio.amateur.antenna From: Dot Subject: Re: Fiberglass roof on FJ-40 Message-ID: References: <11vkrtkc63fde98@corp.supernews.com> Date: Mon, 20 Feb 2006 22:26:44 -0500 On Mon, 20 Feb 2006 17:41:04 -0800, Roy Lewallen wrote: >> I have a fiberglass roof on my Landcruiser, and I was wondering if >>I can use a halfwave roof mounted antenna? >On mine, I mounted a telescoping BC band replacement antenna at the top >of the metal body piece just behind the door and collapsed it down to >about a quarter wave on 2 meters. If it's for 144 or 430 mhz you can actually build a counterpoise that sits right on the roof... A 1/4 wave vertical element connected to the center of our coax and 4 X 1/4 wave ground radials laid out inside the roof liner and secured to prevent rattling. All anyone sees is the whip in the center of your roof. This is easy on the higher frequencies because the radials etc are short (50cm on 2 meters). I've seen this done for 430, 220, 144 and 50 mhz, but wouldn't want to try it for 40 metres [grin]. Article: 221773 of rec.radio.amateur.antenna From: Dot Subject: Re: 2m/440 antenna Q's Message-ID: References: <4a7Kf.49300$dW3.14954@newssvr21.news.prodigy.com> Date: Mon, 20 Feb 2006 22:38:34 -0500 On Sun, 19 Feb 2006 23:28:00 GMT, "Bill Berris" wrote: >Thanks a bunch for any information you can help me out with -- I am looking >forward to getting my feet wet again so that I can convince my wife that I >need more radio equipment... :-) Are you up for a bit of homebrew? Check this out... http://hometown.aol.com/alonestaryank/DESKBUDDY.html Not my design, but I built one for a friend and it works quite well... Article: 221774 of rec.radio.amateur.antenna From: "Frank" References: <1140274674.116569.208960@g47g2000cwa.googlegroups.com> <43F74956.2060207@comcast.net> <43F79966.3070004@comcast.net> <43F8C006.7030806@comcast.net> <43F95307.5020601@comcast.net> <43FA2370.6050906@comcast.net> Subject: Re: using coax shield to create a loading coil ? Message-ID: Date: Tue, 21 Feb 2006 04:35:26 GMT That's correct Dan. I just wanted to systematically build up the antenna, adding a component at a time, to note where the major losses are. This was the first trial with no loading -- except for copper conductivity. >From the other model you sent me it seems that any other attempts are redundant. The major losses are due to ground loss, as expected. Unfortunately this can only be overcome by increasing the length, and number, of radials -- something that is pretty well known. Also inductive loading of the radials does not seem to have any effect, except for marginally decreasing the antenna efficiency. I have been interested in installing a short monopole for 160m, so am very interested in your results. I have a fairly large lot (visible on "Google Earth), so am not so restricted in radial length. 73, Frank "dansawyeror" wrote in message news:43FA2370.6050906@comcast.net... > Frank, > > I tried the nec below. The result was resonant at 21.9 and about 34 Ohms. > I am not competent at reading nec cards yet, however the model editor does > not show any coil loads. That could explain the frequency? > > Dan > > Thanks - Dan > > Frank's Basement 2 wrote: >> Dan, here is a preliminary run on a 12 ft monopole model structured as >> follows: >> base at 6 ft, 10 x 6ft radials. All #14 AWG. Ground - perfect, >> frequency >> 3.8 MHz. >> >> Zin = 0.968 - j1847.55 ohms; >> Efficiency = 87.4 % (structure copper loss); >> Gain = 4.15 dBi; >> Take-off angle = 0 deg; >> Gain at 27 deg elevation (expected TOA with real ground) = +3.09 dBi. >> >> I will try successive modifications to approach a practical model. The >> code >> I used, modified so it should run in 4nec2, is shown below. >> >> 73, >> >> Frank >> >> CM 75 m Vertical 12 ft high >> CM base 6 ft up, 10 X 6 ft radials >> CM copper conductivity >> CE >> GW 1 24 0 0 18 0 0 6 0.0026706 >> GW 2 12 0 0 6 6 0 6 0.0026706 >> GM 1 9 0 0 36 0 0 0 2 >> GS 0 0 .3048 >> GE 1 >> GN 1 >> EX 0 1 24 0 1.00000 0.00000 >> LD 5 1 1 144 5.8001E7 >> FR 0 11 0 0 3.5 0.05 >> RP 0 181 1 1000 -90 0 1.00000 1.00000 >> EN >> >> >> "Frank's Basement 2" wrote in message >> news:dhmKf.6088$_62.3050@edtnps90... >> >>>Dan, >>> >>>The lumped inductance of 4 +j1750 comes from your previous comment about >> >> the >> >>>inductance range from 60 - 90 uH. I just chose the mid range value of 75 >> >> uH >> >>>at 3.8 MHz. To be exact 2*PI*f*L = 1791 ohms. The real part of 4 ohms >>>is >>>based on an approximate Q of 400. >>> >>>Incidentaly I am working at another location this morning. The computer >> >> is >> >>>an old 600 MHz machine, with 384 MB of RAM, and Windows ME OS. The NEC >> >> code >> >>>here takes 17 seconds to run. >>> >>>73, >>> >>>Frank >>>"dansawyeror" wrote in message >>>news:43F95307.5020601@comcast.net... >>> >>>>I see the length is set to 1.8 meters already. A 2 meter elevation >> >> minimum >> >>>is >>> >>>>needed to lower ground effects. >>>> >>>>How is the lumped inductance set of 4 Ohms and 1750 Z? What impedance >> >> does >> >>>that >>> >>>>translate to? How did you calculate this value? Dan >>>> >>>>Frank's Basement 2 wrote: >>>> >>>>>Hi Dan, thanks for the interesting info. You did not specify >>> >>>dimensions, >>> >>>>>but from your comments it appears you are using a vertical about 23 ft >>> >>>high. >>> >>>>>Such a monopole would have a 3.5 ohm input impedance when placed above >> >> a >> >>>>>perfectly conducting ground, and gain about +4.5 dBi. Adding a center >>>>>loading coil raises the input impedance to 11.5 ohms, and gain +2.6 >> >> dBi. >> >>>>>Base loading provides an input impedance of 5.5 ohms with almost the >>> >>>same >>> >>>>>gain as center loading (Q = 400). Adding ten, 6ft radials, at 3" >> >> above >> >>>an >>> >>>>>average ground, the input impedance increases to 40 ohms, and >> >> gain -6.3 >> >>>dBi. >>> >>>>>Adding lumped element loading coils, (75 uH, Q = 400) in each radial >>>>>(antenna base end) drops the input impedance to 37 ohms, and gain -6.4 >>> >>>dBi. >>> >>>>>Don't know why this does not agree with Reg's program. Probably I >> >> made >> >>>some >>> >>>>>fundamental error with the NEC model. Included the code below, so you >>> >>>may >>> >>>>>see an error I missed. >>>>> >>>>>73, >>>>> >>>>>Frank >>>>> >>>>>CM 75 m Vertical 23 ft high >>>>>CE >>>>>GW 1 64 0 0 23 0 0 0.25 0.0026706 >>>>>GW 2 12 0 0 0.25 6 0 0.25 0.0026706 >>>>>GM 1 9 0 0 36 0 0 0 002.002 >>>>>GS 0 0 .3048 >>>>>GE 1 >>>>>GN 2 0 0 0 13.0000 0.0050 >>>>>EX 0 1 64 0 1.00000 0.00000 >>>>>LD 5 1 1 184 5.8001E7 >>>>>LD 4 1 33 33 4 1600 >>>>>LD 4 2 1 1 4 1750 >>>>>LD 4 3 1 1 4 1750 >>>>>LD 4 4 1 1 4 1750 >>>>>LD 4 5 1 1 4 1750 >>>>>LD 4 6 1 1 4 1750 >>>>>LD 4 7 1 1 4 1750 >>>>>LD 4 8 1 1 4 1750 >>>>>LD 4 9 1 1 4 1750 >>>>>LD 4 10 1 1 4 1750 >>>>>LD 4 11 1 1 4 1750 >>>>>FR 0 11 0 0 3.5 0.05 >>>>>RP 0 181 1 1000 -90 0 1.00000 1.00000 >>>>>EN >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>>>Frank, >>>>>> >>>>>>Good morning. Let me start at the beginning. I have a loaded vertical >> >> on >> >>>>>75 >>>>> >>>>> >>>>>>meters. The combination of the antenna and ground measure about 40 >> >> Ohms >> >>>at >>> >>>>>the >>>>> >>>>> >>>>>>antenna. The models all show such an antenna over a perfect ground >>> >>>should >>> >>>>>have a >>>>> >>>>> >>>>>>radiation resistance of between 3 and 4 Ohms. That says the antenna >>> >>>system >>> >>>>>is >>>>> >>>>> >>>>>>less the 10% efficient. >>>>>> >>>>>>This then is a journey to reduce ground resistance. Attempts to add >>>>> >>>>>radials and >>>>> >>>>> >>>>>>wire mesh to the ground have had very little if no effect. This leads >> >> to >> >>>>>Reg's >>>>> >>>>> >>>>>>c_poise model. It predicts a coil in the range of 60 uH to 90 uH tuned >>> >>>to >>> >>>>>a 2 >>>>> >>>>> >>>>>>meter by 18 mm 'wire' will have a total resistance in the 2 to 4 Ohms >>>>> >>>>>range. >>>>> >>>>> >>>>>>Together this should result is a 8 Ohm system. The ratio can be >> >> directly >> >>>>>>inferred as an performance improvement of 5 to 1 or 7 db. This is >> >> worth >> >>>>>some >>>>> >>>>> >>>>>>effort. >>>>>> >>>>>>To answer your question the first step will be one coil and one >> >> radial. >> >>>>>The >>>>> >>>>> >>>>>>objective is the get the antenna system close to 10 Ohms. From there I >>>>> >>>>>will >>>>> >>>>> >>>>>>experiment with adding radials and coils. I am not sure what to >> >> expect. >> >>>>>>Thanks - Dan >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>>Frank wrote: >>>>>> >>>>>> >>>>>>>Not sure I understand what is going on Dan. Are you planning on >>> >>>loading >>> >>>>>>>each radial element? >>>>>>> >>>>>>>Frank >>>>>>> >>>>>>> >>>>>>>"dansawyeror" wrote in message >>>>>>>news:43F79966.3070004@comcast.net... >>>>>>> >>>>>>> >>>>>>> >>>>>>>>These results were from Reg's c_poise program. The band is 75 meters >>> >>>and >>> >>>>>>>>the coils were about 70 uH. The coils were a relatively large >>> >>>diameter, >>> >>>>>on >>>>> >>>>> >>>>>>>>the order of a meter. The wire lengths were about 20 meters. By >>> >>>varying >>> >>>>>>>>the length the coil, the coil wire may be varies from 1mm to 12mm. >>>>>>>> >>>>>>>>Richard Clark wrote: >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>>>On Sat, 18 Feb 2006 08:20:38 -0800, dansawyeror >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>>>The devil is in the details. Modeling shows large coils with 1 mm >>> >>>wire >>> >>>>>>>>>>have a Q in the range of a few hundred. On the other hand a coil >>> >>>with >>> >>>>>12 >>>>> >>>>> >>>>>>>>>>mm tubing has a Q of about 2000. The R of the 1 mm coil is about 6 >>>>> >>>>>Ohms >>>>> >>>>> >>>>>>>>>>while the 12 mm coil is on the order of 1 Ohm. >>>>>>>>>> >>>>>>>>>>Given these model results it says there is a significant >> >> difference >> >>>>>>>>>>between 1 mm and 12 mm coils. >>>>>>>>> >>>>>>>>> >>>>>>>>>Hi Dan, >>>>>>>>> >>>>>>>>>In the details, indeed. What is the LENGTH of wire in this 6 Ohm >>>>>>>>>resistor? What is the LENGTH >>>>>>>>>of wire in this 1 Ohm resistor? How many turns are in these "large >>>>>>>>>coils?" What is their diameter? What is their solenoid length? >>>>>>>>> >>>>>>>>>Without these details, there is nothing said that is significant. >>>>>>>>> >>>>>>>>>73's >>>>>>>>>Richard Clark, KB7QHC >>>>>>> >>>>>>> >>>>>>> >>>>> >>> >> Article: 221775 of rec.radio.amateur.antenna From: "Bill Turner" Subject: Re: What the? Date: 21 Feb 2006 05:28:55 GMT Message-ID: References: <1140240942.959492.40540@g47g2000cwa.googlegroups.com> <7b5hv11irhqeqvjgvpdg5uq8arb7fqpqd1@4ax.com> <1140403097.757516.62600@f14g2000cwb.googlegroups.com> ORIGINAL MESSAGE: KG0WX wrote: > Thanks to all you guys for enlightening me. I did an experiment > - I tuned the dipper to 146.520 (not easy to get it right there) and > took my HT out for a walk. I could hear the carrier out to about > 400 yards! I'm in a wire mesh/stucco/aluminum siding structure > in the city so that kind of output from an instrument is surprising. > > Imagine what it would have done if I inductively coupled to my GP-6 > at 25' ? lol! Next I'll try it on HF with my K2.... > > Ken KG0WX ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Back in the '50s or '60s there was a book published wherein the hero was trapped or something and called for help by sending CW with a grid dip meter. Don't remember any details but it was a great read when I was a teenager. 73, Bill W6WRT Article: 221776 of rec.radio.amateur.antenna From: "Bill Berris" References: <4a7Kf.49300$dW3.14954@newssvr21.news.prodigy.com> Subject: Re: 2m/440 antenna Q's Message-ID: <8cyKf.32832$Jd.22704@newssvr25.news.prodigy.net> Date: Tue, 21 Feb 2006 06:13:24 GMT "WS4V" wrote in message news:vMOdnetFrvIkFGfeRVn-qQ@adelphia.com... > Probably the gutter is made of aluminum if put up in recent years so that > won't work. Put a dual band mobile on a 6"X6" sheet of thin steel and make > four radials about 16" and bend them down at a 45 degree angle from the > corners of the plate. Mount them to the steel plate with small bolts and > nuts. Put the whole thing in the corner of your room. Unless you are in > metal building the antenna will work about as well as it would outside... > and yes it will be light years ahead of a duck. > Ken > remove the X in the address to reply. Thanks for the info... the portability of the design (and the design Dot posted) look great... I will probably try one of those and maybe something like this in addition --> http://www2.arrl.org/tis/info/pdf/0302038.pdf What do you guys think of that one? -- Bill Berris, KF6CNP Salida, CA Article: 221777 of rec.radio.amateur.antenna From: Dot Subject: Re: 2m/440 antenna Q's Message-ID: References: <4a7Kf.49300$dW3.14954@newssvr21.news.prodigy.com> <8cyKf.32832$Jd.22704@newssvr25.news.prodigy.net> Date: Tue, 21 Feb 2006 02:22:22 -0500 On Tue, 21 Feb 2006 06:13:24 GMT, "Bill Berris" wrote: >Thanks for the info... the portability of the design (and the design Dot >posted) look great... I will probably try one of those and maybe something >like this in addition --> http://www2.arrl.org/tis/info/pdf/0302038.pdf > >What do you guys think of that one? It will almost certainly be better than a rubber duckie. And then there's the folded shield dipole I described the other day. Now this one is CHEAP to make... a little coax, some heat shrinkable tubing and a connector. All you do is take a reasonable length of coax (rg-8x recommended in this case) measure back 51.3 centimeters and cut around the cable's outer sheith... DO NOT cut the braid or the inner dialectric. Now cut along the end section of sheilding being very careful not to damage the shield, and remove it. You should now have 1/4 wavelength of exposed shield. Next measure from the end of the cover along the shield by 7500/146 * VF, centimeters (where VF is the velocity factor of your coax). This is usually about .80 in rg-8x so you would measure... 41.09 centimeters, plus a bit for soldering... say 42.5cm. Now cut the shield at your mark and remove the excess... do not cut the dialectric only the shield wires and make sure you get them even as you can (I find an old scissors does a nice job here). Next make a ring of copper wire a bit bigger than the covered part of the coax. Spread out a couple of millimeters of the shield wires and wrap them around the wire ring, then solder with a medium heat iron. This step is to prevent the shield from freying. Now work the exposed shield back over the covered part of the coax. I find it easiest to grab the ring and slide it gently down over the coax. Others have told me it's easier from the bottom of the shield, pulling the shield down as they go... use whatever method gets the job done. Now you should have a length of coax with the center shield exposed for 1/4 wavelength and 1/4 wavelength of shield folded back over the insulated part of the coax. What you have is a dipole. I call it a bazooka dipole, others call it a shield dipole... But it's a dipole. You can now put a connector on the other end of the cable and you're ready to try it out. Hang it someplace where it's not near any metal or concrete obstructions. You should immediately notice that your receiver is more active than with the rubber ducky. Check the SWR, it's likely you'll have to do some trimming to get the lengths right (as with any antenna). You will have to trim the end of the center lead a bit and you may have to scrunch up the shield a bit to get the lengths right. Work in 2 or 3 millimeter increments. If you're careful you should be able to get it down to less than 1.5:1 across the 2 meter band. Once you are satisfied you have it as good as it gets, put the whole thing into a long piece of heat shrink tubing and tighten it up with a blow drier. This keeps water out and prevents the shield from moving, which would upset the match. Your antenna is now complete. Mounting is easy... You can tape a plastic hook on the loose end and hang it from the rafters in your atic or a tree branch. Or, if you want something more perminent, take a piece of 1/2 or 3/4" pvc tubing (the white stuff, not the black) about 2 feet longer than the antenna part of your coax, put a cap on one end, drill a couple of small holes in the other, slide the entire antenna end of the coax into the tube all the way to the top and hold it in place with a couple of plastic wire ties. The extra length is so you can mount it without disturbing the lower arm of the dipole. The tube version can be mounted anywhere... I've clamped them to balcony rails, hung them from overhangs, clamped them to mast posts, even mounted them on car bumpers. Note: the plastic tubing does affect the SWR slightly ... check closely and if it's getting a bit high on the top of the band you may have to clip a little off the end of the exposed center part of the coax to compensate. This antenna will match at 440, but it does so as a 3/4 over 3/4 dipole and the radiation pattern is less than optimal. The launch angle is something like 55 degrees... But at the price (less than $5.00) nothing stops you >from making a second, smaller version for 440 and switching back and forth. Article: 221778 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: What the? References: <1140240942.959492.40540@g47g2000cwa.googlegroups.com> <7b5hv11irhqeqvjgvpdg5uq8arb7fqpqd1@4ax.com> <1140403097.757516.62600@f14g2000cwb.googlegroups.com> Message-ID: <%5GKf.32887$Jd.29320@newssvr25.news.prodigy.net> Date: Tue, 21 Feb 2006 15:12:59 GMT Bill Turner wrote: > Back in the '50s or '60s there was a book published wherein the hero > was trapped or something and called for help by sending CW with a grid > dip meter. Don't remember any details but it was a great read when I > was a teenager. One of the Hardy Boys books was about ham radio. -- 73, Cecil http://www.qsl.net/w5dxp Article: 221779 of rec.radio.amateur.antenna Message-ID: <43FB2F8D.A7725602@nospam.com> From: Gloria Subject: Re: Looking for aluminum tubing/rod in DC/MD area References: <1140474918.828207.324820@g14g2000cwa.googlegroups.com> Date: Tue, 21 Feb 2006 15:19:42 GMT Hi, I know you asked for a local source, I have used this guy on ebay stores, his pricing is very good and he ships us priority mail with tracking. http://stores.ebay.com/TRINITY-METAL-SALES_W0QQsspagenameZFAVQ3aFQ3aSLLRQQtZkm Article: 221780 of rec.radio.amateur.antenna From: xnjljk@shaw.ca Subject: xXx AMATEUR CAM IN BATHROOM xXx 1877 [2/2] Message-ID: Date: Tue, 21 Feb 2006 15:27:20 GMT begin 644 HidenBathCam29.1.06.scr M35J0``,````$````__\``+@`````````0``````````````````````````` M````````````````````@`````X?N@X`M`G-(;@!3,TA5&AI,P@23)=#$K0^P1TH8A!'J*>AQ6J%81;8&*(\"(8B+AJ=>H6*L0FB:#UKR<; M`7H@"VK^HI*).:V`3`,0+C!@__L?S"D[.70U4B0DL5V:C:J8S7`+(06#&R&X MX53_7Z_1UW\PH>!CLD/B@[7?ZO4K\HFK#E%[J8MDM`@0=?^WA20B>H3H>M-G MA7WB.H7`?_@$A)G!,/PLEH_>%*6,"9`9#+!T3'LUROT2L/!#FCCO)"(>X"_1 M_#$`#C1V@V+.4`Y[D6'N#[4TA"-N!,+1['X:I0L]1CM5K?;G!8AK"!"AL`0# MS-$@#%3%58#F1IP9@D)4X@@!>4$Q=X!GS\8O!S6UC(.5GLM*=$D)I(U13+MT MY=(%GM`-FGA1IJ]-K8)T&^L-6"T,!T)HX\<$%Z<,F*&4"#+!4Y!^0U/V*.QY M'"WN>A?[KY:S0#$D#(@%CTY_+"R?DP66&0,AM-*PD'6/+$0>$!#W0<_)]4TE M@A3^P"<%56#T898$H?'LE!=U"H!ES\'3CT7:X0.AT2OX_\SL=2(,(AT0FN73 M)*0E#CBB55)*LTEY/@5L1_*`9H>*OF"S)'G`2(5A#`M+S2C-F8HMX.,+OOIG M(``K0-$7&)'$PRB2A!R>\Z0GCXD15/Y-$V_NN@*,T62'P/:!D7VT"/O&LY`'1]\%.'P<@7^^5>\*"QV,BNP MJ10^(.[F$^!1.HKW0X7Y'M`GQR@%(,;=[F#U7_=XS@@.&&<%A,J&C)LX=`T6 M)(S`24"EJW]6@F64\<3<4K"NVK\$@;/(`*(V:_!9676IY0)IX+B7VP\C_-,) M-F:')YXM^5TIY_#'J+H#<1;?%L(4@83'$WT'-V20P@#V+[+Y)RX1N%P<7&$*1;J+@_A`D-,2+EAWN3-@K$LY.!+@5J(BZ,P1D4JZVS!$CR.0>W_+$17K6H*Z*BI M&_@\M!\SZVD.CQZSG`R%4<4+[%JBXW0UA-94U;J0<2=?=K#\,"85H17M_&'0 M6OP'!7\-H:4H>CMH0?A9[YD&CC&H2KP=Q\@Z/K#PQ`%C1B6PTH)]"^6O?,,O MTQ/\EF^"@W!QO<;<5E/W,_>`5OC@_&]21!RO]YQ<!5WA&8!(U":Z5:9=B1 MW,G7R*HJID6SQG80L;#^\`:PQ$%LBH_P?BQ`H-YJ8T M9I#",HAQSGZJ?J!0([>D*`5M:$)0++2+H@VWZWG0`R;@WTBY[LZ+FHGTBU26 M9535\J"O+3#8C2F:9GQ28%:0B@36US%D5*16':@_^IE=$':+>>K!+Y/$^\'/ M*^!&SLM;0\F<7IQ-&JO5]9RZ=-^&C7O-0(X&%BAVH((G$!#\D+G@K4'C':"8 MH$P>7H7F^24\C7!?TT.*+2JETZT,!!D_/T88[3*P!UU4TCPF,6#`H MY2\'[CF8(A`0\*+7"YP;AAQ10OP0[56W%AR0[E%`YO/W_..9XF!0`Y+&%$]Q MF^9ZLT>1;CKC,6H*T,4E,\?O\@N]H4H)&N0T4!-QOILZ6["L*.A%Y/\>1AXFA M(/8=3,GM9-$/_8_!#Q-$H[A,8")-VT)"1(Z`)!O!20OGKI5YF0:G'*QO9$4J M,B/T%;H)F[;8E)8#-K>=9>8NQ?65"#XQ:/LKSK)UJI.B)B-CVC"E@[,`;/U? M!H;$>D&(+=0*_-$QE1414_;)AA`3(JQ+65(GF1M<^8'W(%J>AED"J8T^I9[Z M+'.^"+U<&>H43S8U]E!W[ZQY'Z..H^=!#$9O%HWP9R-\!?]+A/P)'J=EE7I(,4J.PDUQ]E/:TP\6*)FDDB>0*"RLI`N'76P(D<^0`K\#%H6F=,]7CC^JHM)%2@^\0`E3?W^ M<&8>F@GA<:')=)O?LQ$GXK\&M<[PKI7Z$UN6C'_5FU*ZPL0)*0C"/S+1D@Y8 MX0-*%9ZZ,*CP.(CN?V;44U4!%IR#$H&*DMY!S'0;&A`TL$.'5$K3L%-A4!_F' M96Q($1Y=;'Z$@P-0U(N-0T"A\"+HH"$.I0(K1J*-!;M\&QJ6G<:AD^)201KW M'[3%"P&-&N',30)LB79A74Z$98Z*EN*#!LBXC[APP@%:<&]Z10)%P+@P`,B7 MX_1@++=0E/OJWK!T0\`5U,8@:KW4H1`MU&P4+.`Y4RH6# M;`D5,X(;]%Z8`Z)IM:LM0)-O8RM@(`B(FD5K$VE"'1`)7D2:Z=I/Z*J`'B.K M`H$!RNHD6JRHQ&@#N9ZFCVBI$0S1%C%6/B!I"2K;==(!)]4N_X-WBH,6=U)_ M15;YR37WH6Y(%+[!7+U=SJ(OE/A6T-0?/R=:X0TY-,9/.)__=V"]&'+46GT] MJ[*+!`5H%8%23@"<$(B3U<]'^Q!"]W]#M$DGX%]H3';]3".LN6-4.PQ12ZD0 M,EJ,\MZ-BX!P7#6$[97KID'#QBG.95J9W2MG4SB=,ONL]#MMH MZ4_2L`JY4VHC[JV"-!=&Q,O)"?OI=\YLC[`V!.#A,5P[:!_T#)3^A)RXLX)$ M()`&8:"5U5>80"MJ?1;@""6L%1%,6^1M&^WAB>'%V3'N8(A27"%%$`\5F;H] M0^DG6F:BFLE@80NA5!.)VIH!6UA912I9PZ#L?LR9/6KO/<"`DL`CT%JK#(KY M$Q6&^T01:"W6E3Q;"\NM-8"@EMJ3$O=%RXDT8JLP@3U0_&3PUAIB\)%:TJP! ML##A3NPF]CQ0\6$I3X@J1?AH%>#H^I8I=B?\[,`K5L-5SZ>>:$I))9O&8EX> M#T(CRWZ.8FJ3K&`F(/^^F#<(*3?5%A%\K*FB&4`PT%B&GFAH0;K;$X-C*8$$ M:+T'M(5T([TI@DL:HC#V:#\A1>)+.7[/45$GVA<)NX]K`/6W!5(KKML7+Q#% M-IT^N/C[*R8BF!W@+'/%B-.2Y%'U;`K^UY!!%M/-=)OUEL ME_.CG28G^F2C%D*X[LDR\M4ID5::&?!<%2?@`1R$)QKSCBH(/:!+99\ MS15#2DBNND2?4N;1)M)0QR/Z%J'I8U-HHDWD$V]/RLHCWG;YLEOG,UB1#GKV MR@LG7=PM6K;GB@]T@HBG>+1N93<,6&BJ9W-><[73]4R=A).98)-5+KIJ+4II MTV+(15:!=M%S*+8;IE8`U>7C$$&$7X1`.;]!C+MHYK;)ZA0T1@I[MPH(4Q?C M7_KP*PIU'&$6OO!:Z<)?VG+15=D$5G_IX+Q-4U6.#*RC2 M).<&-,9<>;2*54L5V0+^WR'W<5:)T>B-Q*ZCQ1#25HXB^#J>&S,UD!QUF^#G M2>,_FSH>42(/31_4:C2FJ<1>S`6>T,IZH5K^-AQM1N]E\ZF5U_5&8H)%9;"G MZYE<*%U_(%((=PI(Z47CC@^7U7QJB!WI4KQR9X)2R:5HIQ3'8E40\Z(@;:CM MJW:LEY6QD4"8+_[0N].0^,FFT:A?3 MH4T)^DO=>;GE&4*HCT!Y0H6,T MF!P9)O7`:P M[T5KD7%I^RZ7T-N<%FQ>#7KER/KMQ/9C84H*=*12;EI[I1(D@$B5HPM\T@X6_K M*]KY^M.E1XGD4,0D2A/U0>%8;Z2HX\^*0&PH6J1\5!)7"V)6H7;X11;ARK*E M!`044:.Q)47K>HUV7$H?:.DSFB$"8EVN$(D%B7;1!R52I$9)8RCF"%6,9A?& M]OMI`*)C-)Q7$PNXN09RJ7H)E+S`RT84"S:4U9GN8^7`(U5JV2JH,A&%EQ)C M"X$RNZ(NTI#^\^4N$UT.E9_4'[@EJ#(U8^N];Z<8WAI,`528'_Z.Y0/HOHF@ M&C&*_X#&U9]M[8`7%9T,B2844%XN?9^-4W1*T^#+@C3>LA@5^TRZ+<[PTZLV\B'OAZ8@5LPCY,K:"!A6I@S&9$7"%G7`V![ M8=]:B#:ZF/;VYAUT2>O7ZY#%HA9'#0,IBUG6CU9C%SUCL=E81!#J7F&PK,0- MF17C!?T(_X)$&D)S(/!V@,:(%P`$H=9BA6L@` MJ!30A5+!AHX1ZC?>%?+D82!],![&-:I[06#](LZ_&`%\$73+;P"[QV/L4WWS MR3YQLH65VD@5V-.E[KF4.8_Z@#'VSWV%;7;JHL7(R.VGC$>6W^OZD^U-I>%T MKL"GW.CG!;=SFJOWK"@#E&J,Z[V3Y?C:]0L13[[45["&OQ\\<0SJIZB4'_-3 M1(]$KADVAY.L3$?,:.53T(+I5,9I+U[9UG$U@)LH.Q7KR*+;3L93+XV/;^'9 MG.-(WD!^=&W[3VLL!,_/O%8*\-:L6H%H6:[XCM8*_?G\6;[^^>YE>#PM#9&R MCV*$R,*4`BSK!AY*HIF%>2<2JR11YU3A>UJ"T)$[Z=LI&YNO0N`J,=OGJ;25 M[-`PD!9-'3/6)&4QEFTD(D8U02Y4=9D$0HL.-(15S46*DI(4*K-*NW3U*K>T M_LM&8F+TE5?9L#'U+=1)]K13A]-5654"^C(>*`H('!]ED`&3/\O0+1%$7]I6 MB6K3!&78?-7R70\#<[0#U`I*I+X5;1GR+K@(.G0_$:=U.9KZPR8,!BP7OS\K MB7:&HBHNM4X_\QSBRM.FRX^]M0%IY8?^$1T&9:`4\\45YJ>AE'6*Y6$6OD3@ M`*(,%-D:+]:+))C8#G;D2S6Z9A_U]VG53I4?Z-#S+US/ MQVA5*)1EPHH?TI4A7@%S'C7*EF&^W_;0))CY`L=A_L.YA*)+-HMMSLJ\HA"J M\BRO',%&$%$`#7YN<"-(=SN;7(_P5[FSIC0XKN)"ZODJ'IYR$C$>AA#9@46P M3)A942$6Q\1)%@UF1;1U>4NT4MMSY*KFU]UIE"W*?/DQP?0J,-PI0PL4Y)V$ MG>XY@(*%2'FS_`Y>9IT97"64*3K#1E3%Q[ZHX-@@2-*_(Y'+`/-"(VG"-6C M3'UW-:0VMU$IJH4@6J*6(^+ZM'(L?^.E)F`[7\HF#B">@/:!I81-"M)3!X_1 MLUC'G?GXX#C%;CNQB,P1K0ER_TA%^.[3\@3M8Z)B=\K)GW&;!:E,,A7M(K3M M('2TAI_840L$@0_1?NWI,)Y]H3=ZL1FY)T?9O7%[L@O:P;H;5?64T7[H!"Z& M1"`Y5".!M7SM(%BB+*$_'BO0TM2]VGL/?KD:&`5LN!IF[=3,+`%9A]$^A1C))02* MI8!^CJ"/86]EFEI)?(!/VGND:]255+P:8BV/`*U6WF(BBPQ%;&.D7^Z!7E!" M61M_-=**%Y%W.>D#!M,G@>#A604F6H9=[^A4NFYN&6YQ@L!V2YI@+.PKK)7XW)55Y0U6N71BV(R-'IG#J!X9I%Z.570ACX^2>E[PO;?OA\#CO,FL29J%YT8]3/6H49#K!)HGRYH&^N?U_#< MI#BD*"HL*!)&K7K0RF+.AT+'[\11X!0 MSN:-<$#Y]&S_^%8B%4:>(U&U<+[S$`.`XISLT3L+? MPY%^YK`&QSBDE$1BQJ>T< MH^F-SVL47^8?)H%U%8JS0.+,$%-A))@+T&52]/7%7T,@!H/115/%:%E M*DJV@Z'`J[1[Q';TM$W]0=6/U1_]8SF!EC$:!!06565MLD2!8>.^=8->-;ND M$=31N*B*J^VEA=)6I)`*S.-ZBNI+S4$P?`XIT=6)$_8`E4"T!1.`(/0N"E$X MF%;:BI45=&R@96V;Y)Q-DFER@4-*IXKC:_7E"A)D>H=EI$!;:B\Q%K=AK]54 M9X,Z@=S]H\NF"S)O,D#R09:WQK@L$3BQ"(N9LFY563]::^:V=(&B%4HUG&R1 M4:C*X=#W0[[PB@Q@/:=P5*.6"P4#[6PN!Q8+58'T^P8V='O,LN-NYR4*$JEI MF0I1\;#E@5TM#M%MNU]>50;S80FC3F9@M912J]"#1;ZH4"I#]##!_4R5$;@N MS:*:0=*H3VNY/6VJ?-URRU%LGJZ'")7`SJ#J-*,]E?4Z4$J675Y(E4)1(JXW M.N!ZF]\D/7E.13\C@].NK;SBA[K;H_6/J;C3UJ9XX'NR5_;BUVD55<[ZQ4@Z M"!M?!630NXQ+#%0Q+E9%/H<.0-$[6O&J.2D:X8UV(D]-JQ-['[[Y7HLPG931 M3B<*EJK*O_QD,!LM]\["66VT$"F*T#?@%@[_LQXHK74[^LK2I;WR] M)Q_[GJ_:CEMJ90#^2AITSCT-B9LOK("[^<*)76M>%0)H+TD_.WJ@HWHO)A[I MM\L>5\"H@/?*E.O`U@D!N4,`/(*(0XA3=$/?XHL`$$5Y0`+Q55"_MABJ"UU< MMS#$(HN>A44+#:('=:,T3+C+>E@$T=15B3RZ[1EGCS,/[5NSHK`?-<&GE+]; M&*YE*U_.V+JJ\48+U#&HH1V"GQ@IQ.2C+3%0T*J$%^B1.*J*\"1+_KP][&@= M%%2@V$?DY:;AK,68Y,9H<85)6E6)E2"ZB?QQC/UR396[&5H9M&Y`B0`I^B;6 M[@GMM65S?0K)!MXM.R3IJ$"K(^I!"M8X+63,C47+G*8P_^1 MD<6J)8P/95G7^43M:!DR.?4MJ-`;G[:AKTI!-3VC&JKZ5-Q^H[:2(UM=R^G9B87?^T4KL M>TJ59=>IVSOBD7<^,O&.L-)Y/F(IS<+KTP.Q@F_U5M2Z('SKXV[CR399'6+B M0U=VZVKU6<31^J/-;5M#7[("'2Z&*Z MJHAI,4`140F6/HA@F`+#=+WV$'05O"*HH@'`?70I@/UD^R2>$/M$]^G734/2 MJ/D1^N'U^?O0I92K/*"W%'8Z.9A!>$"[M9")<<)IPIDU^*NU/XB!^U=4^+CF M,>N*_`EW%;4CZE8ZC0OO8EOU1^&`!`1*P,SHYX!]/\QPVJ%5!X+Y=4%OX0?K MVZSHFKD:$#.3E,%'M-/5[QQ[B6KVR;[3]`' MKA_&A5"X)J!@,P+Z&,RC?D6XZ7*_(N""[OT3DSNJ*P($(P=8!'`$/6M7!;=M MS:8IGO=_8!D=UQX#\&Z-.I(0:]2M53KD6EE3LV M;G2FD"[])>F4%EM*1:Y7H[0EH#NW$A"B5!@/A!PUXQI MESS$1F;*W`A?8!20MF[8N16R924TVNV$!2RR80$!VMK(7('!)!`0&L(6`H:& M#8VP_7!7PJ7!B?!Y>VA@@[&1F-T`781@&Q]YO)S`.J&S<:M+`W'X#:%;6 M4+20EPC#A/E2IN%!Y3-6J$#FPH8#RU4`)B+%0%6&3M)EE>507*A1;I6[W2(MFI MGH&4M!E.R*Z:LXLRMR38B45-=,M20O"60@,'<"-.@B0-IVZ&1+B/+MNYTMDB5R\IO654-)'-@J0L&'G-DPI=IP`HNW+H5 M6;;MAPE9&-`CH8T`N&.IX-.20%V`7J1-P-3>LH\&,5Q<>N`A")V9RV6@)OV\ M16JF8=W2K6=.T!.&@+%84J%6(K7HT*=7C$4R-$,TZ3%JH>JD)."FVV8'(6$@1JU>N]5.QBQD%=Q^I:C`"#9A+ M]+7HAHLQ8U&"3KVJ,:7`3!<CBO9NT1MFJ(1\N8E"E7#>%EBU4+(#+W`MRUK2( M"-0).')!5BZ)`-S4"+K.`DEG19<.!=345ZJP"7X6W4M0HBM%NA6TF:%QS4(` M14[3TC2@D'E9Y0"74=DV/F00J(4QX/2FG0-B7+0H31;03I19Z)Z*B"N";R"I M6NC1Z(=0W*3QU+LPMIJJS0/+MS"!T_L6L%Z&)2F4("VX&URQ$H38M(V5Q5(I MP]&_H6@F0TIXT<7;2-V6T(#JPX&$@4+"AB1P2(U+IZV3%@2X,,',!D@L-)RE MPP)P00(/HH.RT&`*4.)G[`I0`7>83I84",`0Z[(M2;J$0Z-9@I*@#T"'H&7V$J,)=0A1Z)Y&CVT&LK=]#:L')%&!,"-`1)G MB7%QYS#8Y"7J$A$J+04EDA$`E9A*-%BB*X%KB;/$S"7>$J&7N$N-4,(OI$01 M,J`22XG`2E0EXBNQE8FRA%@5UA)HAS=':`B0*E*G(Q+]B%4H0C,&2#(EI!%` MEMA*7"@[B`&"+9&6B;D$7`#R$G4D)<&/1H#81BFQE#BJ!%2BMA)8"1A+?"4! M+5&6`QXS5?`(P!W4)>02D9>X2X1?8B\BE)J@DA)'"7!*+"5B*A&5B:R$526^ M$EQ5*$N(2O?-2DH@M9IC+7B+T`K=NJM3!4%]RW:HPB*]S%EER&XH89C)`*K: MX$PE2S'#0+>J4#VLG&3E05@*R()"`*@W*R+`WZN/H`,3R^'0(C!FXJ(8:'"% MI+5+N41;"Q6&..C"F$N6E=F-45U8#U-)WDG8BQJFS4)!,$C:0"BK8'/#>J+, MROTJV4U3(,_!MBZ,`SNG-\8P3E)84(9D.[1HU*-=).2=*@5HVPM04%20ELQ# M%02H6"B"E$`U%!X45+B5F`PMUHY-2Q@VK+R[K1+"-03$C6SD7ZFKLLT,&+Z[;O*\Q`%3.2B*!%="`FUI@ZID;8`( M-$9AG@,P7:L%BSL^-0H&(\,RE@S;LW@.3RX$%/.DI<#+RR$&6QA@#%@5)X]Y M!!T_7$19FBFY?%`>+2P'6[-P6-.:FL):SH:5L/!ZA'C!CX,'4+MQ5P`++@XE M,DM;E1_0H?@@@93$;%VJ4N#(V.+I6U>5PZ:E3A'@ZRP\E,):Y3DGH>I>Y4^+ M`HOFG2Q;3&%X$-8$_BE@B$H2^P8Z4U.CP"(N81X`!]WLMZY;F,X5$`8`R'NI MC$4[==K-94MP0!@Q5MBO,-#&@%YO?5BR?NW.*DDPU,^3`W^QO&)EY0S"]+`K MO9+(KV$,P,1ZCU&P$?ZP+O[4V,E7H0RB1G4UV&5N4ED[?)0YQP>(6-C&I=N\ MHYLH*SX*@C&+8:A!8POL$L)%U8L#S0V*H(6(W,[*H@Y5;%>!=CICUFIFUFKK M0"EV(C"06H:-`0K?;3FBH.;6(KAH,T`-#1`#7N)M1F*D4XG6GX1I43AE1SJA M@(*.`*=)D0BH%D43F$1QI!9=2N''E`]`60"LNB>P*%U3QBX6!#RIT:!4!!0J MQ2H$0":6""P*.C)1L:A9,K&O%X$%`:I2A](7,(L+UQ&8A``BD0H`````__]0 MC84`_O__4&@JDD``C84`_O__4&@EDD``:)V60`"-A0#\__]0Z!$`00>#Q""- MC0#\__^#R/]`@#P!`'7Y:@!0C94`_/__4FF5_/O__PP"``#_-!4T9$`````` M`-CLB#$````````#``,````H``"`#@```$```(`0````6```@`````#8[(@Q M`````````0`!````<```@`````#8[(@Q``````$```#H``"`B```@`````#8 M[(@Q`````````0`!````H```@`````#8[(@Q`````````0`)!```N``````` M``#8[(@Q`````````0`)!```R`````````#8[(@Q`````````0`)!```V``` M``"Q```(!@`````````````(MP``%```````````````'+<``/P"```````` M``````<`00!0`%``20!#`$\`3@```````````"@````4````*`````$`"``` M````X`$```````````````````````#___\`_?W]`+Z^O@"ZN+@`N[FY`(:' MAP"`@(``P,#``#`P,```````JZZO`/#O[P!K:VL`75U=`+2RL@!R<7$`AH2$ M`*RJJ@#7U]<`T-#0`,G(R``X-S<`.#DY`)>5E0"^OK\`=W9V`(V,C`#4TM(` MN+>W`,3$Q`"HIZ<`1T='`$Q,3`#.S]``[M[5`*:GJ`!85U<`JJFI`)R:F@!> M7EX`?WQ\`,7$Q`#FYN8`?'Q\`$E*2P#&QL8`2TM+`(>&A@!V=G8`.CHZ`$]/ M3P"LK*P`GIZ>`$A(2`!!04$`B8B(`%A86`"*BHH`,3$Q`*&@H`!)24D`='1T M`/GY^0#__OX`8F)B`#0T-`"?G9T`34U-`(*"@@"WM;4`Y.7E`(^/CP!]?'P` M[>WM`+R\O`!Z>GH`S7D`C(R,`+FY MN0"ZNKH`MK:V`)V=G0!_?W\`*RLK`"\O+P`S,S,`*BHJ`!@8&``:&AH`$Q,3 M`!L;&P`U-34`-C8V`#L[.P`*"@H````````````````````````````````` M```````````````````````````````````````````````````````````` M```````````````````````````````````````````````````````````` M```````````````````````````````````````````````````````````` M```````````````````````````````````````````````````````````` M```````````````````````````````````````````````````````````` M```````````````````````````````````````````````````````````` M```````````````````````````````````````````````````````````` M```````````````````````````````````````````````````````````` M```````````````````````````````````````````````````````````` M```````````````````````````````````````````````````````````` M```````````````````````````````````````````````````````````` M```````````````````````````````````````````````````````````` M````````````````````````````````````````````````5Q$7%QH&&4<1 M"P``"TU5`````$TW!P0W10,H4A<:$BD/#4(````^-U$20UD-!RTH)Q&RE24R@7%``````+%P``114@-@X2&SLD4E)1``````<" M``!.,F8G44U1$PTR)!$`````.QM%*0`2)A).*!D;$%A2%P`````F)A4V`P$^ M`!I/;B@[-AD7/@```!HG-C80&R`40#8?#3LN&29)````-R0V-B@4)Q0G-A\G M'A\9)@L````7!E@U%Q0B*A!!%4<.6"@7/@```#L.%S<[1QD.&Q`031I91R8` M````*1%,11 M%`%,)!``)"0`87:D$```87>D$```87BD$``NWL1```# MG>J00``#G>:00`!3B\.+^RVLD$``B86MD$``C;6LD$``N4`$``#SI8O[P[T` M````B_>#QE2!Q_\0``!65U=6_Y7:D$``B\A>7XO!P?D"\Z4#R(/A`_.DZR90 M`@$`/`(!``@"`0```$```,```````0"'VX?;A]N'VX?;A]N'VTI#JQ`````` M``"^]N(@C0"%;-QC!EHT/K@#N28)4-F[,71@[@S(YQ-`Q"U!M:5)`&($0=3: M_V40\$3_8BEH=PZX%5T"E`=P.GBO\%G;&R7=X1B060S6GHTO[EU4UH"AU]*$ MM5*M0FK4JQ8LM(]^"+PP2[CX3'G0^FK8TF;"+6$@],4;JZUO6.I5Y`5GJ-V' MU6C@8(!+@(@;O5>K5E9(DR_<^,E"A2*`S?]G,C$&\'95*F0"0CN8,O@8!Q`D M/AAQD"Y9_5>O+*#/O7EPUTA@:DC?/@#!IYV'G1O#5$RMB0-D&2*HV],;P:-0:V3Z3/_P/M3VY2 M[Q/"Q2N7RX.+S0W($SU[:G#:*MV2%UCWY"9.^`-63`$%Y1ZUV'UN[>N'0>!E M,5F'=0%!B#ZX#4,$3O'PE<13OI$@F'XPP0]LKR]%Y!F0H.^`/EY/T*@+5U-> MJ"=""$&=K_19OR)JZ@HPR`4,C=XVVD*ILW:NJI\2:!6H1!LIK*7H*=E[L`YN MP`YHC3^%D%P/69;)+0@85;+R8@-2FAO"DGHUQ@+"0K"PU>O)6!ZL/M/`4>7& M(HE%K<=6:6)+*@0XA?3\[]_90K6$E0*)&='B"`H'F`=;21CIVE]_H-UPKCU$ M+\DME*L8^J5@_/#K1O@D_W!,B%GX'"XV@(40\;$CL&[R`HOU'&B4-FL-$^=A M5;A'6@HGEAHUW0C79-4J-0))LAM<+%WE@L$'9YE@^T(/]TA]<`=,[O&!P0.# M!(BT!7N@$)=*=K9`PBBN5/M``PPL3#)11G-#C0%J),(+BLQ%I=W]6W7CX.O6YH&`/[`$QF:!SYP9GD,YH0$, M!+K$4.D?827"@X*'Z\88$`4!!($/VYYH3==00-Z$Z0:OH<*L\RJ7KMENH(/->0"#M*`1S*;9AJ2`IF)(9#,A`8Q#;!QYC,1LP!S":L,!0Z("$O)I.C.VT MI=8"`1>1*[8"W))!\7`GPN59@18Z!`4N=8S@CL:NI0P/6G1J569DSI1&)$R) MDKEEFU#+V;#8AO>M<,;F+LC&;%?"F`ZP8*"]*<@Y%J?#$;OUT_\?8%/;K)"Q M+H5C`]F7@I[4$```!'9710\"1"0,B`=' MZ\8#TG4(BQ:#Q@3Y$](/@FX!```#TG4(BQ:#Q@3Y$](/@]P```"Y!````#/` MC:0D`````(UD)``#TG4(BQ:#Q@3Y$](3P$EU[TATL0^)[P$```/2=0B+%H/& M!/D3TG-"O0`!``"Y"````#/`C:0D``````4``````])U"(L6@\8$^1/2$\!) M=>^(!T=-==8#TG4(BQ:#Q@3Y$])RP^DF____N0$````SP(VD)`````"-I"0` M````D`/2=0B+%H/&!/D3TA/`277O@\`'B40D$,9$)`P`@_@(#X3J_O__N0@` M```SP(U)``/2=0B+%H/&!/D3TA/`277OB$0D#.G&_O__N0<````SP(VD)``` M``"-I"0`````D`/2=0B+%H/&!/D3TA/`277OB^BY`@```#/`C9L``````])U M"(L6@\8$^1/2$\!)=>^+R(O%@\$"A<```"#^0(/A.T```!!,\"0 M`])U"(L6@\8$^1/2$\!)=>^)1"04Z4;^__^Y`0```)`#TG4(BQ:#Q@3Y$](3 MR0/2=0B+%H/&!/D3TG+D24EU,8O#N0$```"-I"0`````B_\#TG4(BQ:#Q@3Y M$](3R0/2=0B+%H/&!/D3TG+DZ6D```!)B\&+3"04B^@SP-/E,\`#TG4(BQ:# MQ@3Y$](3P$EU[PO%B]BY`0```(V;``````/2=0B+%H/&!/D3TA/)`])U"(L6 M@\8$^1/2.#TP$SPX/&!(/I!'05@_D$<^BZ!````"O1*_*Y!````.O8BW0D M(#M&!G0$,\#K!HO'*T0D)%Y?6\G""`````````#````,````MC`````````` M```````````````````````````````````````````````````````````` M```````````````````````````````````````````````````````````` 5```````````````````````````` ` end Article: 221781 of rec.radio.amateur.antenna From: nvqpqw@shaw.ca Subject: Moms Dildo Lesson To Sister Caught On My Secret Camera ! 910 [1/2] Message-ID: Date: Tue, 21 Feb 2006 15:47:33 GMT hello I setup a secret camera in my sisters bedroom 1 night and only caught my mom teaching my sister how to use a dildo. Download pics here.. lsndiysbcdcovygjwxoxzjweusrkogcpsqrvljywrtrhetvmsrjjfhtvccgwszxrvdjfzuitnzsytubdjisjxvysx Article: 221782 of rec.radio.amateur.antenna From: "Bob Spooner" Subject: Re: Fiberglass roof on FJ-40 Date: Tue, 21 Feb 2006 10:58:05 -0500 Message-ID: References: <11vkrtkc63fde98@corp.supernews.com> "Roy Lewallen" wrote in message news:11vkrtkc63fde98@corp.supernews.com... > ... But having spent quite a few hours studying various patents for their > design, it looks like some might work much better than others. > > Roy Lewallen, W7EL > Roy, Would you share with us which ones you think would work better? 73, Bob AD3K Article: 221783 of rec.radio.amateur.antenna From: Dot Subject: Re: Is there any simulation software of antenna? Message-ID: References: <1140535522.641436.276000@o13g2000cwo.googlegroups.com> Date: Tue, 21 Feb 2006 11:08:37 -0500 On 21 Feb 2006 07:25:22 -0800, "Jackie" wrote: >thanks. There's tons of software for simulating antennas. The easiest to use is this one... http://mmhamsoft.ham-radio.ch/ Article: 221784 of rec.radio.amateur.antenna From: "JIMBO" References: <1140404823.199601.294020@g43g2000cwa.googlegroups.com> <1140541577.324412.146060@g43g2000cwa.googlegroups.com> Subject: Re: Usenet Kook Alert .... Lyle Blake Message-ID: Date: Tue, 21 Feb 2006 17:06:19 GMT > newsgroup he is claiming that Industry Casnada is denying him the > ability to take the Ameteur Radio test because of his gender > presentation (he is makle but like to dress in woman's clothes). Gender Presentation!!!!! in Casnada !!!.........A makle in wummins clothes...BONA Article: 221785 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Fiberglass roof on FJ-40 Date: Tue, 21 Feb 2006 10:07:46 -0800 Message-ID: <11vmlnn27fg50f4@corp.supernews.com> References: <11vkrtkc63fde98@corp.supernews.com> Bob Spooner wrote: > "Roy Lewallen" wrote in message > news:11vkrtkc63fde98@corp.supernews.com... >> ... But having spent quite a few hours studying various patents for their >> design, it looks like some might work much better than others. >> >> Roy Lewallen, W7EL >> > > Roy, > > Would you share with us which ones you think would work better? > > 73, > Bob AD3K Sorry, it's been nearly 20 years since I went through the patents, and I don't recall all the various modifications and innovations I came across. And I don't have any idea which might have been included in commercial designs. Surely someone has done some comparative measurements of various commercial units and published the results. If not, it sounds like a good project for someone interested in using through-glass antennas. I'm not one of them. Roy Lewallen, W7EL Article: 221786 of rec.radio.amateur.antenna From: Dot Subject: Re: Usenet Kook Alert .... Lyle Blake Message-ID: <5mlmv11avigicgfifafdsgejcl3grhsli3@4ax.com> References: <1140404823.199601.294020@g43g2000cwa.googlegroups.com> <1140541577.324412.146060@g43g2000cwa.googlegroups.com> <1140542227.813378.26820@g14g2000cwa.googlegroups.com> Date: Tue, 21 Feb 2006 13:11:12 -0500 On 21 Feb 2006 09:17:07 -0800, "Mike G4KFK" wrote: > >diannamelrose@gmail.com wrote: >(utter drivel) > >Why have you cross-posted this stupid thread from >rec.radio.amateur.antenna into uk.radio.amateur? Because it has more negative impact on me if she does. Next, she's going to accuse me of doing it! That's her sickness... she goes into a newsgroup makes a pissing mess of the place, floods it with anon postings, makes all kinds of wild accusations, gets the whole place flaming hot... and then blames me. She's out to make a mess of my life any way she can. Fortunately she's not very good at it and mostly my friends and I just sit around and laugh at her latest bout idiocy. If you keep track it's pretty obvious what she's doing. Anyway... just toss the wanker in your kill files and forget about her. Article: 221787 of rec.radio.amateur.antenna From: Mike Coslo Subject: Re: demodulator & detector Date: Tue, 14 Feb 2006 14:16:21 -0500 Message-ID: <43F22C85.7080402@psu.edu> References: <1139513435.028624.39500@g43g2000cwa.googlegroups.com> <1139890757.855341.190720@g44g2000cwa.googlegroups.com> Ron J wrote: > So sorry, I figured that the antenna folks would no more about it > because after all, there are modulators and demodulators in our > transmitter and receiver circuits. What else is interesting in the > antenna world? Did the DLM and EH antenna combine into one? ;-) > Not to worry, Ron, cuz his post was just another drive-by flame from a poster who prefers to remain anonymous. Most who do try to remain anonymous have a good reason - and it's not the one that they give ;^) - 73 de Mike KB3EIA - Article: 221788 of rec.radio.amateur.antenna From: "stargatesg1" References: <1140474918.828207.324820@g14g2000cwa.googlegroups.com> <43FB2F8D.A7725602@nospam.com> Subject: Re: Looking for aluminum tubing/rod in DC/MD area Message-ID: Date: Tue, 21 Feb 2006 20:10:59 GMT You might also try metal scrap yards in your area. they can sometimes order tubing at very good prices. "Gloria" wrote in message news:43FB2F8D.A7725602@nospam.com... > Hi, > > I know you asked for a local source, > I have used this guy on ebay stores, > his pricing is very good and he ships > us priority mail with tracking. > > http://stores.ebay.com/TRINITY-METAL-SALES_W0QQsspagenameZFAVQ3aFQ3aSLLRQQtZkm > > > Article: 221789 of rec.radio.amateur.antenna Message-ID: <313030303837383543FB79CE79@zetnet.co.uk> Date: Tue, 21 Feb 2006 20:36:30 GMT From: Dave Piggin Subject: Connectors Hi to all. > What's the correct designation for the Female ? "UHF" feed lines are usually and commonly terminated with a 'N' Type plugs into a 'N' Type Socket. "VHF" fed lines are usually and commonly terminated with PL259 plugs into a SO259 Socket. The indicator, PL represents a Plug, and SO represents a Socket. If you think of it in a bodily manner, relate to it as Male= PL and Female= So, and so a [male enters the female] Take a look at any "UHF" transceiver and you will find that it's a 'N' Type socket on the rear entry of the rig, a far superior plug to the PL253/8/9 Etc Etc Series. Dual band transceivers are terminated at the rear by a PL259 socket. Hope this helps. Cheers Dave. -- 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: 221790 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: using coax shield to create a loading coil ? Date: Tue, 21 Feb 2006 21:01:02 +0000 (UTC) Message-ID: References: <11vc4ntcub1k91@corp.supernews.com> <1140207382.882131.11500@z14g2000cwz.googlegroups.com> <11vctsaacbdfa57@corp.supernews.com> <1140228740.616862.294460@g14g2000cwa.googlegroups.com> <11vd24h21qefea@corp.supernews.com> <1140266886.722102.279930@z14g2000cwz.googlegroups.com> <11vecbaciouhcda@corp.supernews.com> <11vkk5vrumlac0a@corp.supernews.com> "Roy Lewallen" wrote in message news:11vkk5vrumlac0a@corp.supernews.com... > Reg Edwards wrote: > > > > Roy, you seem to have forgotten proximity effect. > >. . . > > Forgotten? I just didn't see what relevance it had on the difference in > Q between an inductor made from a braided coax shield and one made from > solid tubing. And I can't see from your posting anything which adds to > that discussion. But maybe I'm missing something? > > Roy Lewallen, W7EL ======================================= Yes, Roy, you are missing something. Article: 221791 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: 20 Meter Dipole - instant DX!!! Date: Tue, 21 Feb 2006 21:26:43 +0000 (UTC) Message-ID: References: "Radio TexMex" wrote > Before someone beats me too it, I've already had somebody point out the > goofy flaw with my new super awesome 20M dipole. And after doing some much > needed reading on baluns, I've concluded that the 4:1 balun isn't needed. > > Readers: Please be patient. Learning process taking place here. > ======================================== Reading about 4:1 baluns makes one imagine a 4:1 balun is cessary - whereas most likely it isn't. ---- Reg. From "know code" Fri Feb 24 00:33:14 EST 2006 Article: 221792 of rec.radio.amateur.antenna Message-ID: <43FB8752.2010907@wanadoo.nl> Date: Tue, 21 Feb 2006 22:34:10 +0100 From: know code Reply-To: "know code" User-Agent: Thunderbird 1.5 (Windows/20051201) MIME-Version: 1.0 Newsgroups: rec.radio.amateur.antenna,uk.radio.amateur To: Dot Subject: Re: Usenet Kook Alert .... Lyle Blake References: <1140404823.199601.294020@g43g2000cwa.googlegroups.com> <1140541577.324412.146060@g43g2000cwa.googlegroups.com> <1140542227.813378.26820@g14g2000cwa.googlegroups.com> <5mlmv11avigicgfifafdsgejcl3grhsli3@4ax.com> In-Reply-To: <5mlmv11avigicgfifafdsgejcl3grhsli3@4ax.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Lines: 29 Organization: Wanadoo NNTP-Posting-Date: 21 Feb 2006 21:34:09 GMT NNTP-Posting-Host: s5591cd23.adsl.wanadoo.nl X-Trace: 1140557649 dr3.euro.net 85254 85.145.205.35:2021 X-Complaints-To: abuse@wanadoo.nl Path: news1.isis.unc.edu!arclight.uoregon.edu!news.uni-stuttgart.de!news.belwue.de!news.germany.com!multikabel.net!feed20.multikabel.net!news2.euro.net!postnews2.euro.net!news.wanadoo.nl!not-for-mail Xref: news1.isis.unc.edu rec.radio.amateur.antenna:221792 uk.radio.amateur:267101 Dot wrote: > On 21 Feb 2006 09:17:07 -0800, "Mike G4KFK" wrote: > >> diannamelrose@gmail.com wrote: >> (utter drivel) >> >> Why have you cross-posted this stupid thread from >> rec.radio.amateur.antenna into uk.radio.amateur? > > Because it has more negative impact on me if she does. > Next, she's going to accuse me of doing it! > > That's her sickness... she goes into a newsgroup makes a pissing mess of the > place, floods it with anon postings, makes all kinds of wild accusations, > gets the whole place flaming hot... and then blames me. > > She's out to make a mess of my life any way she can. Fortunately she's not > very good at it and mostly my friends and I just sit around and laugh at her > latest bout idiocy. > > If you keep track it's pretty obvious what she's doing. > > Anyway... just toss the wanker in your kill files and forget about her. > You really think we care how she messes with you? Here's a clue, we don't! -- Article: 221793 of rec.radio.amateur.antenna From: Dot Subject: Re: Usenet Kook Alert .... Lyle Blake Message-ID: References: <1140404823.199601.294020@g43g2000cwa.googlegroups.com> <1140541577.324412.146060@g43g2000cwa.googlegroups.com> <1140542227.813378.26820@g14g2000cwa.googlegroups.com> <5mlmv11avigicgfifafdsgejcl3grhsli3@4ax.com> <43FB8752.2010907@wanadoo.nl> Date: Tue, 21 Feb 2006 16:46:18 -0500 On Tue, 21 Feb 2006 22:34:10 +0100, know code wrote: >> Anyway... just toss the wanker in your kill files and forget about her. > >You really think we care how she messes with you? Here's a clue, we don't! [sigh] We've never even spoken and already you are hostile. I don't care if you care or not... just don't be getting me caught up in her stupidity. Article: 221794 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: For Roy Lewallen et al: Re Older Post On My db Question Date: Tue, 14 Feb 2006 14:15:20 -0800 Message-ID: <11v4lk1dlthe02f@corp.supernews.com> References: <11v4fg75rhomo98@corp.supernews.com> <6236-43F24589-857@storefull-3255.bay.webtv.net> Owen Duffy wrote: > > I shouldn't use that work ONLY!!! > > Only in a DC circuit, or a in an AC circuit (loop) where the current > and voltage measured are in phase. In an AC circuit where the voltage > and current are not in phase you must multiply the product of the RMS > voltage and RMS current by the cosine of the phase difference to get > real power (which is what I think you mean by "average power"). > Of course, that only works when the voltage and current are sinusoidal and of the same frequency. More generally, the average power is 1/T times the integral over T of v(t) * i(t) dt, where T is the interval over which it's being averaged. If the waveforms are periodic, an interval of one cycle can be used for T. Roy Lewallen, W7EL From "know code" Fri Feb 24 00:33:15 EST 2006 Article: 221795 of rec.radio.amateur.antenna Date: Wed, 22 Feb 2006 00:21:56 +0100 From: know code Reply-To: "know code" User-Agent: Thunderbird 1.5 (Windows/20051201) MIME-Version: 1.0 Newsgroups: rec.radio.amateur.antenna,uk.radio.amateur Subject: Re: Usenet Kook Alert .... Lyle Blake References: <1140404823.199601.294020@g43g2000cwa.googlegroups.com> <1140541577.324412.146060@g43g2000cwa.googlegroups.com> <1140542227.813378.26820@g14g2000cwa.googlegroups.com> <5mlmv11avigicgfifafdsgejcl3grhsli3@4ax.com> <43FB8752.2010907@wanadoo.nl> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Lines: 18 Message-ID: <43fba094$0$85254$dbd41001@news.wanadoo.nl> Organization: Wanadoo NNTP-Posting-Date: 21 Feb 2006 23:21:56 GMT NNTP-Posting-Host: s5591cd23.adsl.wanadoo.nl X-Trace: 1140564116 dr3.euro.net 85254 85.145.205.35:2021 X-Complaints-To: abuse@wanadoo.nl Path: news1.isis.unc.edu!canoe.uoregon.edu!newshub.sdsu.edu!newsfeed.freenet.de!213.132.189.2.MISMATCH!multikabel.net!feed20.multikabel.net!news2.euro.net!postnews2.euro.net!news.wanadoo.nl!not-for-mail Xref: news1.isis.unc.edu rec.radio.amateur.antenna:221795 uk.radio.amateur:267123 Dot wrote: > On Tue, 21 Feb 2006 22:34:10 +0100, know code wrote: > >>> Anyway... just toss the wanker in your kill files and forget about her. >> You really think we care how she messes with you? Here's a clue, we don't! > > [sigh] We've never even spoken and already you are hostile. You crosspost your crap to uk.radio.amateur and you wonder why people are hostile? Jeez, some people! If your 'friend' posts to uk.r.a with the crap you claim, there are enough people here who could tie her up in knots and make he wish she'd never bothered :) -- Article: 221796 of rec.radio.amateur.antenna From: "DieSea" References: <1140404823.199601.294020@g43g2000cwa.googlegroups.com> <1140541577.324412.146060@g43g2000cwa.googlegroups.com> <1140542227.813378.26820@g14g2000cwa.googlegroups.com> <5mlmv11avigicgfifafdsgejcl3grhsli3@4ax.com> <43FB8752.2010907@wanadoo.nl> <43fba094$0$85254$dbd41001@news.wanadoo.nl> <1140564265.889829.196500@z14g2000cwz.googlegroups.com> <8h8nv1l8i18bk8ajei1jtlub4j5l66hm96@4ax.com> Subject: Re: Usenet Kook Alert .... Lyle Blake Date: Tue, 21 Feb 2006 23:48:35 -0000 Message-ID: <43fba6d2$0$29574$da0feed9@news.zen.co.uk> RATHER A GOOD IDEA YOU CAN PUT ME IN YOUR KILL FILE AS WELL Not only for SHOUTING but for TOP POSTING AS WELL Bye Bye DieSea "Dot" wrote in message news:8h8nv1l8i18bk8ajei1jtlub4j5l66hm96@4ax.com... > On 21 Feb 2006 15:24:25 -0800, "Mike G4KFK" wrote: > >> >>know code wrote: >>> If your 'friend' posts to uk.r.a with the crap you claim, there are >>> enough people here who could tie her up in knots and make he wish she'd >>> never bothered :) >> >>Is this a 5-minute argument or the full half-hour? > > It's over. I've just put all concerned in my kill files. Including you. > > Article: 221797 of rec.radio.amateur.antenna From: "David G. Nagel" Subject: Re: Stealth antenna question Date: Tue, 14 Feb 2006 19:02:38 -0600 Message-ID: <11v4vdvs7jeerab@corp.supernews.com> References: <5eudnRTUMuRG9m_eRVn-qA@comcast.com> Joe S. wrote: > I am considering installing a stealth antenna on the porch of my first-floor > apartment and would like some suggestions. Here's the deal. > > -- First floor apartment. > -- Porch is a concrete slab, 10 X 10. > -- The ceiling of the porch is the underside of the balcony of the apartment > above me. It's all wooden. > -- Thus, the ceiling of my porch is 10 X 10, wood. > > How about I build a 40-meter dipole, 67 feet long, feed with coax and a > balun in the center. Attach the coax and the balun to one of the corner > posts that supports the balcony above my porch. Run the two sides of the > dipole in opposite directions, but, instead of stretching the wire straight > as I normally would if hanging the dipole from trees, towers, etc., what if > I run the wires around the underside of the balcony deck? This would give > me a horizontal loop made up of two pieces of wire, each 33.5 feet long, > with the loop being 10 feet on a side, thus, each end of the dipole would > run around underneath the balcony deck and come back almost to the center of > the dipole. > > That is -- the balun would be secured to one of the corner posts. One piece > of wire, 33.5 feet long would run straight out from the balun along the 2 X > 8 rim joist for 10 feet, make a 90-deg turn (20 ft), run another 10 feet and > make another 90-deg turn (30 ft), and end up 3.5 feet after the third turn. > The other end of the dipole would do the same thing, only run in the > opposite direction. At the balun, the two wires making up the dipole would > run at a 90-deg angle to each other. And, the two wires would overlap (or > be only a few inches apart) for 27 feet of their length. > > I probably didn't explain this idea too well but I'd like to hear some > suggestions. Thanks. > > What ever you do make sure that your neighbors upstairs aren't exposed to excessive RF Radiation. Dave WD9BDZ Article: 221798 of rec.radio.amateur.antenna From: "David Thompson" References: <1139323498.740521.243970@o13g2000cwo.googlegroups.com> Subject: Re: Noisy Antenna Message-ID: Date: Wed, 22 Feb 2006 04:12:21 GMT Glenn, I suspect you just have a noisy environment. You probably need a noise machine such as the ANC-4 or MFJ 1026. You might also try a noise antenna such as a K9AY loop. I have one K9AY loop and it really helps pull them >from the noise. I am fairly quiet on 80 but very noisy on 160. 73 Dave K4JRB Article: 221799 of rec.radio.amateur.antenna From: "Sal M. Onella" References: <1140420029.713791.128680@g47g2000cwa.googlegroups.com> Subject: Re: Low power 5w FM Transmitter antenna Message-ID: Date: Tue, 21 Feb 2006 20:35:40 -0800 wrote in message news:1140420029.713791.128680@g47g2000cwa.googlegroups.com... > Hello, > > A friend of mine live in outback NSW and wants to install a 5w FM > Transmitter on his property to transmit music between buildings - 88 - > 108mhz - can anybody suggest an antenna for this purpose - maybe a link > to manufacturer/distributor in Australia? Yes we understand that it is > most probably illegal but think that signal will not drift off > property. > > Thanks in advance. > First, 5W will likely go out 5 miles. I know because 100 mW will go beyond 1/2 mile, per my own tests. Please appreciate the interference potential of that unlicensed 5W signal. The ideal antenna for this is the folded dipole antenna, hand-made of TV receiving twin-lead wiring -- the flat stuff, consisting of two conductors having about one centimeter spacing. You make the antenna with that leadwire and you feed it with that same leadwire. You must NOT have any of it run along or against metallic material of any type. That's what stand-offs are made for. Have a look at http://www.wisegeek.com/what-are-fm-antennas.htm , especially the dimensions in the second paragraph. Antennas are reciprocal; one that works for transmitting will work for receiving, so you build two. You can fasten the antennas to wood sticks for their physical support (essential for a medium as floppy and flexible as twin-lead). Let us know how this progresses. (Makes the typing seem worthwhile.) I see the actual construction details are lacking in the reference I offered. Then try this one, too: http://www.kgnu.org/howtohear/antenna.html Good luck. Article: 221800 of rec.radio.amateur.antenna From: "Sal M. Onella" References: <1140474918.828207.324820@g14g2000cwa.googlegroups.com> Subject: Re: Looking for aluminum tubing/rod in DC/MD area Message-ID: Date: Tue, 21 Feb 2006 20:51:29 -0800 wrote in message news:1140474918.828207.324820@g14g2000cwa.googlegroups.com... > I'd like to design and build a new 2-meter Yagi antenna, and would > like to construct it using aluminum tubing and rod. Drawn tubing--the > stuff with an axial seam--would suffice. > > Anyone know of a good source for this stuff in Washington DC or nearby > areas in Maryland? I've tried Home Depot and the like, but the stock > available in these places is incomplete and expensive. > > -Dave, K3WQ > I use my stash of busted-up TV antennas from behind the garage. Trouble is, I'm in California and thus of no help to you. Do you or your neighbors have a wasted TV antenna on a reachable roof or chimney??? John KD6VKW (Fort Meade, 1970 - 1972) Article: 221801 of rec.radio.amateur.antenna From: "Sal M. Onella" References: Subject: Re: Fiberglass roof on FJ-40 Message-ID: Date: Tue, 21 Feb 2006 21:23:36 -0800 "Harbin" wrote in message news:sOmdnbJ0OueQx2fenZ2dnUVZ_v6dnZ2d@adelphia.com... > Howdy Y'all: > > I have a fiberglass roof on my Landcruiser, and I was wondering if I can use a halfwave roof mounted antenna? > For some reason, I think since the halfwave is end loaded, that it will not work on my fiberglass roof, and that > it uses a steel roof as part of the match. Am I wrong here? The only other thing I can think of is some kind of > stainless steel J pole on a mount coming off the back. And what about a dual band that will work on fiberglass? > Anybody work with this problem before? > > SeeYaa:) Harbin > > Vehicle roof-mounted antennas are commonly quarter-wave whips. I know there are 5/8 wave whips but I am not prepared to address their use. How flat is the roof? If it's flat enough to permit you to cement a sheet of steel to it, then use a mag-mount. I know the sheet of steel needs to be only about the size of a TV tray, since that's what I used and got a good match with an MFJ El-Cheapo dual band magmount. (I happened not to be using it on a vehicle roof; however, the TV tray made a satisfactory ground plane, anyway.) My non-ham buddy used this basic method on his motor home roof for a magmount CB antenna that was much longer than the MFJ dual-bander. It never blew over and the sheet of steel never came loose. So, can you glue/cement/bond/rivet/nail/staple/tape a 2-ft by 2-ft piece of galvanized steel to your roof? (Caution: Stainless is often non-magnetic.) I love J-poles. I make them out of copper pipe but have no vehicle experience with them. The J-pole is a half-wave antenna that works great in free space and requires no ground plane. More? Article: 221802 of rec.radio.amateur.antenna From: "Sal M. Onella" References: <313030303837383543FB79CE79@zetnet.co.uk> Subject: Re: Connectors Message-ID: Date: Tue, 21 Feb 2006 21:30:53 -0800 "Dave Piggin" wrote in message news:313030303837383543FB79CE79@zetnet.co.uk... > Hi to all. > > What's the correct designation for the Female ? > > "UHF" feed lines are usually and commonly terminated with a 'N' Type > plugs into a 'N' Type Socket. > "VHF" fed lines are usually and commonly terminated with PL259 plugs > into a SO259 Socket. > The indicator, PL represents a Plug, and SO represents a Socket. > > If you think of it in a bodily manner, relate to it as Male= PL and > Female= So, and so a [male enters the female] > Take a look at any "UHF" transceiver and you will find that it's a 'N' > Type socket on the rear entry of the rig, a far superior plug to the > PL253/8/9 Etc Etc Series. > > Dual band transceivers are terminated at the rear by a PL259 socket. > Hope this helps. Cheers Dave. > > -- > 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. Might not the socket connector be called SO-239? I did a quick "Google" before sending this. Article: 221803 of rec.radio.amateur.antenna From: "Sal M. Onella" References: Subject: Re: ?? anyone have plans on how to build a usb gps antenna for laptop Message-ID: Date: Tue, 21 Feb 2006 21:47:04 -0800 wrote in message news:IyQKf.18144$Ug4.11471@dukeread12... > > > http://64.71.184.220/eng/gpspatch.txt http://www.arrl.org/tis/info/pdf/0210036.pdf http://vancouver-webpages.com/peter/gpspatch.gif Article: 221804 of rec.radio.amateur.antenna From: "Lee" References: Subject: Re: ?? anyone have plans on how to build a usb gps antenna for laptop Message-ID: Date: Wed, 22 Feb 2006 08:05:43 GMT "Sal M. Onella" wrote in message news:RUSKf.130$Uc2.57@fed1read04... > > wrote in message > news:IyQKf.18144$Ug4.11471@dukeread12... > > > > > > > http://64.71.184.220/eng/gpspatch.txt > > http://www.arrl.org/tis/info/pdf/0210036.pdf > > http://vancouver-webpages.com/peter/gpspatch.gif Any more designs to suit a Garmin 310 ??? Lee .....G6ZSG..... Article: 221805 of rec.radio.amateur.antenna Message-ID: <43FC679E.47A8BBC3@atc.fam> From: Alice Subject: Re: Is there any simulation software of antenna? References: <1140535522.641436.276000@o13g2000cwo.googlegroups.com> Date: Wed, 22 Feb 2006 13:31:10 GMT hi jackie, http://www.eznec.com/ checkout the demo version. 73 alice Article: 221806 of rec.radio.amateur.antenna From: "Bill Turner" Subject: Re: Low power 5w FM Transmitter antenna Date: 22 Feb 2006 15:07:34 GMT Message-ID: References: <1140420029.713791.128680@g47g2000cwa.googlegroups.com> ORIGINAL MESSAGE: Sal M. Onella wrote: > First, 5W will likely go out 5 miles. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Better than that, 5w will go to the horizon and slightly beyond. On HF, I have worked China with 5 watts. 73, Bill W6WRT Article: 221807 of rec.radio.amateur.antenna From: "Frank's Basement 2" References: <1140274674.116569.208960@g47g2000cwa.googlegroups.com> <43F74956.2060207@comcast.net> <43F79966.3070004@comcast.net> <43F8C006.7030806@comcast.net> <43F95307.5020601@comcast.net> <43FA2370.6050906@comcast.net> <43FA9D68.3060807@comcast.net> Subject: Re: using coax shield to create a loading coil ? Message-ID: Date: Wed, 22 Feb 2006 16:39:35 GMT Dan, Will be interested to know how you get on with the antenna. I suspect that adding loading coils to radials is about the same as adding loading coils to any part of an antenna system. They do nothing to effect the radiation efficiency, only modify the input impedance. 73, Frank > The effect of the radials is a surprise. I would not expect that short radials > would work well at all? The system predicts about 9 Ohms. That is closer to what > is expected and over 6 db better then the 50 Ohm reading. > > I will try experimenting and let you know. > > Thanks - Dan > > Frank wrote: > > That's correct Dan. I just wanted to systematically build up the antenna, > > adding a component at a time, to note where the major losses are. This was > > the first trial with no loading -- except for copper conductivity. > > > > From the other model you sent me it seems that any other attempts are > > redundant. The major losses are due to ground loss, as expected. > > Unfortunately this can only be overcome by increasing the length, and > > number, of radials -- something that is pretty well known. Also inductive > > loading of the radials does not seem to have any effect, except for > > marginally decreasing the antenna efficiency. > > > > I have been interested in installing a short monopole for 160m, so am very > > interested in your results. I have a fairly large lot (visible on "Google > > Earth), so am not so restricted in radial length. > > > > 73, > > > > Frank > > > > > > "dansawyeror" wrote in message > > news:43FA2370.6050906@comcast.net... > > > >>Frank, > >> > >>I tried the nec below. The result was resonant at 21.9 and about 34 Ohms. > >>I am not competent at reading nec cards yet, however the model editor does > >>not show any coil loads. That could explain the frequency? > >> > >>Dan > >> > >>Thanks - Dan > >> > >>Frank's Basement 2 wrote: > >> > >>>Dan, here is a preliminary run on a 12 ft monopole model structured as > >>>follows: > >>>base at 6 ft, 10 x 6ft radials. All #14 AWG. Ground - perfect, > >>>frequency > >>>3.8 MHz. > >>> > >>>Zin = 0.968 - j1847.55 ohms; > >>>Efficiency = 87.4 % (structure copper loss); > >>>Gain = 4.15 dBi; > >>>Take-off angle = 0 deg; > >>>Gain at 27 deg elevation (expected TOA with real ground) = +3.09 dBi. > >>> > >>>I will try successive modifications to approach a practical model. The > >>>code > >>>I used, modified so it should run in 4nec2, is shown below. > >>> > >>>73, > >>> > >>>Frank > >>> > >>>CM 75 m Vertical 12 ft high > >>>CM base 6 ft up, 10 X 6 ft radials > >>>CM copper conductivity > >>>CE > >>>GW 1 24 0 0 18 0 0 6 0.0026706 > >>>GW 2 12 0 0 6 6 0 6 0.0026706 > >>>GM 1 9 0 0 36 0 0 0 2 > >>>GS 0 0 .3048 > >>>GE 1 > >>>GN 1 > >>>EX 0 1 24 0 1.00000 0.00000 > >>>LD 5 1 1 144 5.8001E7 > >>>FR 0 11 0 0 3.5 0.05 > >>>RP 0 181 1 1000 -90 0 1.00000 1.00000 > >>>EN > >>> > >>> > >>>"Frank's Basement 2" wrote in message > >>>news:dhmKf.6088$_62.3050@edtnps90... > >>> > >>> > >>>>Dan, > >>>> > >>>>The lumped inductance of 4 +j1750 comes from your previous comment about > >>> > >>>the > >>> > >>> > >>>>inductance range from 60 - 90 uH. I just chose the mid range value of 75 > >>> > >>>uH > >>> > >>> > >>>>at 3.8 MHz. To be exact 2*PI*f*L = 1791 ohms. The real part of 4 ohms > >>>>is > >>>>based on an approximate Q of 400. > >>>> > >>>>Incidentaly I am working at another location this morning. The computer > >>> > >>>is > >>> > >>> > >>>>an old 600 MHz machine, with 384 MB of RAM, and Windows ME OS. The NEC > >>> > >>>code > >>> > >>> > >>>>here takes 17 seconds to run. > >>>> > >>>>73, > >>>> > >>>>Frank > >>>>"dansawyeror" wrote in message > >>>>news:43F95307.5020601@comcast.net... > >>>> > >>>> > >>>>>I see the length is set to 1.8 meters already. A 2 meter elevation > >>> > >>>minimum > >>> > >>> > >>>>is > >>>> > >>>> > >>>>>needed to lower ground effects. > >>>>> > >>>>>How is the lumped inductance set of 4 Ohms and 1750 Z? What impedance > >>> > >>>does > >>> > >>> > >>>>that > >>>> > >>>> > >>>>>translate to? How did you calculate this value? Dan > >>>>> > >>>>>Frank's Basement 2 wrote: > >>>>> > >>>>> > >>>>>>Hi Dan, thanks for the interesting info. You did not specify > >>>> > >>>>dimensions, > >>>> > >>>> > >>>>>>but from your comments it appears you are using a vertical about 23 ft > >>>> > >>>>high. > >>>> > >>>> > >>>>>>Such a monopole would have a 3.5 ohm input impedance when placed above > >>> > >>>a > >>> > >>> > >>>>>>perfectly conducting ground, and gain about +4.5 dBi. Adding a center > >>>>>>loading coil raises the input impedance to 11.5 ohms, and gain +2.6 > >>> > >>>dBi. > >>> > >>> > >>>>>>Base loading provides an input impedance of 5.5 ohms with almost the > >>>> > >>>>same > >>>> > >>>> > >>>>>>gain as center loading (Q = 400). Adding ten, 6ft radials, at 3" > >>> > >>>above > >>> > >>> > >>>>an > >>>> > >>>> > >>>>>>average ground, the input impedance increases to 40 ohms, and > >>> > >>>gain -6.3 > >>> > >>> > >>>>dBi. > >>>> > >>>> > >>>>>>Adding lumped element loading coils, (75 uH, Q = 400) in each radial > >>>>>>(antenna base end) drops the input impedance to 37 ohms, and gain -6.4 > >>>> > >>>>dBi. > >>>> > >>>> > >>>>>>Don't know why this does not agree with Reg's program. Probably I > >>> > >>>made > >>> > >>> > >>>>some > >>>> > >>>> > >>>>>>fundamental error with the NEC model. Included the code below, so you > >>>> > >>>>may > >>>> > >>>> > >>>>>>see an error I missed. > >>>>>> > >>>>>>73, > >>>>>> > >>>>>>Frank > >>>>>> > >>>>>>CM 75 m Vertical 23 ft high > >>>>>>CE > >>>>>>GW 1 64 0 0 23 0 0 0.25 0.0026706 > >>>>>>GW 2 12 0 0 0.25 6 0 0.25 0.0026706 > >>>>>>GM 1 9 0 0 36 0 0 0 002.002 > >>>>>>GS 0 0 .3048 > >>>>>>GE 1 > >>>>>>GN 2 0 0 0 13.0000 0.0050 > >>>>>>EX 0 1 64 0 1.00000 0.00000 > >>>>>>LD 5 1 1 184 5.8001E7 > >>>>>>LD 4 1 33 33 4 1600 > >>>>>>LD 4 2 1 1 4 1750 > >>>>>>LD 4 3 1 1 4 1750 > >>>>>>LD 4 4 1 1 4 1750 > >>>>>>LD 4 5 1 1 4 1750 > >>>>>>LD 4 6 1 1 4 1750 > >>>>>>LD 4 7 1 1 4 1750 > >>>>>>LD 4 8 1 1 4 1750 > >>>>>>LD 4 9 1 1 4 1750 > >>>>>>LD 4 10 1 1 4 1750 > >>>>>>LD 4 11 1 1 4 1750 > >>>>>>FR 0 11 0 0 3.5 0.05 > >>>>>>RP 0 181 1 1000 -90 0 1.00000 1.00000 > >>>>>>EN > >>>>>> > >>>>>> > >>>>>> > >>>>>> > >>>>>> > >>>>>> > >>>>>> > >>>>>>>Frank, > >>>>>>> > >>>>>>>Good morning. Let me start at the beginning. I have a loaded vertical > >>> > >>>on > >>> > >>> > >>>>>>75 > >>>>>> > >>>>>> > >>>>>> > >>>>>>>meters. The combination of the antenna and ground measure about 40 > >>> > >>>Ohms > >>> > >>> > >>>>at > >>>> > >>>> > >>>>>>the > >>>>>> > >>>>>> > >>>>>> > >>>>>>>antenna. The models all show such an antenna over a perfect ground > >>>> > >>>>should > >>>> > >>>> > >>>>>>have a > >>>>>> > >>>>>> > >>>>>> > >>>>>>>radiation resistance of between 3 and 4 Ohms. That says the antenna > >>>> > >>>>system > >>>> > >>>> > >>>>>>is > >>>>>> > >>>>>> > >>>>>> > >>>>>>>less the 10% efficient. > >>>>>>> > >>>>>>>This then is a journey to reduce ground resistance. Attempts to add > >>>>>> > >>>>>>radials and > >>>>>> > >>>>>> > >>>>>> > >>>>>>>wire mesh to the ground have had very little if no effect. This leads > >>> > >>>to > >>> > >>> > >>>>>>Reg's > >>>>>> > >>>>>> > >>>>>> > >>>>>>>c_poise model. It predicts a coil in the range of 60 uH to 90 uH tuned > >>>> > >>>>to > >>>> > >>>> > >>>>>>a 2 > >>>>>> > >>>>>> > >>>>>> > >>>>>>>meter by 18 mm 'wire' will have a total resistance in the 2 to 4 Ohms > >>>>>> > >>>>>>range. > >>>>>> > >>>>>> > >>>>>> > >>>>>>>Together this should result is a 8 Ohm system. The ratio can be > >>> > >>>directly > >>> > >>> > >>>>>>>inferred as an performance improvement of 5 to 1 or 7 db. This is > >>> > >>>worth > >>> > >>> > >>>>>>some > >>>>>> > >>>>>> > >>>>>> > >>>>>>>effort. > >>>>>>> > >>>>>>>To answer your question the first step will be one coil and one > >>> > >>>radial. > >>> > >>> > >>>>>>The > >>>>>> > >>>>>> > >>>>>> > >>>>>>>objective is the get the antenna system close to 10 Ohms. From there I > >>>>>> > >>>>>>will > >>>>>> > >>>>>> > >>>>>> > >>>>>>>experiment with adding radials and coils. I am not sure what to > >>> > >>>expect. > >>> > >>> > >>>>>>>Thanks - Dan > >>>>>>> > >>>>>>> > >>>>>>> > >>>>>>> > >>>>>>> > >>>>>>>Frank wrote: > >>>>>>> > >>>>>>> > >>>>>>> > >>>>>>>>Not sure I understand what is going on Dan. Are you planning on > >>>> > >>>>loading > >>>> > >>>> > >>>>>>>>each radial element? > >>>>>>>> > >>>>>>>>Frank > >>>>>>>> > >>>>>>>> > >>>>>>>>"dansawyeror" wrote in message > >>>>>>>>news:43F79966.3070004@comcast.net... > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>>>These results were from Reg's c_poise program. The band is 75 meters > >>>> > >>>>and > >>>> > >>>> > >>>>>>>>>the coils were about 70 uH. The coils were a relatively large > >>>> > >>>>diameter, > >>>> > >>>> > >>>>>>on > >>>>>> > >>>>>> > >>>>>> > >>>>>>>>>the order of a meter. The wire lengths were about 20 meters. By > >>>> > >>>>varying > >>>> > >>>> > >>>>>>>>>the length the coil, the coil wire may be varies from 1mm to 12mm. > >>>>>>>>> > >>>>>>>>>Richard Clark wrote: > >>>>>>>>> > >>>>>>>>> > >>>>>>>>> > >>>>>>>>> > >>>>>>>>>>On Sat, 18 Feb 2006 08:20:38 -0800, dansawyeror > >>>>>>>>>> wrote: > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>>>The devil is in the details. Modeling shows large coils with 1 mm > >>>> > >>>>wire > >>>> > >>>> > >>>>>>>>>>>have a Q in the range of a few hundred. On the other hand a coil > >>>> > >>>>with > >>>> > >>>> > >>>>>>12 > >>>>>> > >>>>>> > >>>>>> > >>>>>>>>>>>mm tubing has a Q of about 2000. The R of the 1 mm coil is about 6 > >>>>>> > >>>>>>Ohms > >>>>>> > >>>>>> > >>>>>> > >>>>>>>>>>>while the 12 mm coil is on the order of 1 Ohm. > >>>>>>>>>>> > >>>>>>>>>>>Given these model results it says there is a significant > >>> > >>>difference > >>> > >>> > >>>>>>>>>>>between 1 mm and 12 mm coils. > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>>Hi Dan, > >>>>>>>>>> > >>>>>>>>>>In the details, indeed. What is the LENGTH of wire in this 6 Ohm > >>>>>>>>>>resistor? What is the LENGTH > >>>>>>>>>>of wire in this 1 Ohm resistor? How many turns are in these "large > >>>>>>>>>>coils?" What is their diameter? What is their solenoid length? > >>>>>>>>>> > >>>>>>>>>>Without these details, there is nothing said that is significant. > >>>>>>>>>> > >>>>>>>>>>73's > >>>>>>>>>>Richard Clark, KB7QHC > >>>>>>>> > >>>>>>>> > >>>>>>>> > > Article: 221808 of rec.radio.amateur.antenna From: "Frank" References: <1140274674.116569.208960@g47g2000cwa.googlegroups.com> <43F74956.2060207@comcast.net> <43F79966.3070004@comcast.net> <43F8C006.7030806@comcast.net> <43F95307.5020601@comcast.net> <43FA2370.6050906@comcast.net> <43FA9D68.3060807@comcast.net> Subject: Re: using coax shield to create a loading coil ? Message-ID: Date: Wed, 22 Feb 2006 18:11:46 GMT "Cecil Moore" wrote in message news:p11Lf.51233$dW3.24862@newssvr21.news.prodigy.com... > Frank's Basement 2 wrote: >> I suspect that >> adding loading coils to radials is about the same as adding loading coils >> to >> any part of an antenna system. They do nothing to effect the radiation >> efficiency, only modify the input impedance. > > Wherever did you get that idea? A dipole made out of > 80m hamsticks is less than 1% efficient. Well, I guess I should have said: "... do nothing to effect the radiation efficiency, except possibly reduce it". Don't know anything about "Hamsticks", but they must have lousy loading inductors! Frank Article: 221809 of rec.radio.amateur.antenna From: "Steve Nosko" Subject: Re: Connectors Date: Wed, 22 Feb 2006 12:28:57 -0600 Message-ID: References: <313030303837383543FB79CE79@zetnet.co.uk> Yup! It's not a "might"... PL-259 (male) mates with the SO-239 (female) 73, K9DCI "Sal M. Onella" wrote in message news:GFSKf.127$Uc2.111@fed1read04... > > "Dave Piggin" wrote in message > news:313030303837383543FB79CE79@zetnet.co.uk... > > Hi to all. > > > What's the correct designation for the Female ? > > > > "UHF" feed lines are usually and commonly terminated with a 'N' Type > > plugs into a 'N' Type Socket. > > "VHF" fed lines are usually and commonly terminated with PL259 plugs > > into a SO259 Socket. > > The indicator, PL represents a Plug, and SO represents a Socket. > > > > If you think of it in a bodily manner, relate to it as Male= PL and > > Female= So, and so a [male enters the female] > > Take a look at any "UHF" transceiver and you will find that it's a 'N' > > Type socket on the rear entry of the rig, a far superior plug to the > > PL253/8/9 Etc Etc Series. > > > > Dual band transceivers are terminated at the rear by a PL259 socket. > > Hope this helps. Cheers Dave. > > > > -- > > 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. > > Might not the socket connector be called SO-239? I did a quick "Google" > before sending this. > > Article: 221810 of rec.radio.amateur.antenna From: "Frank" References: <1140274674.116569.208960@g47g2000cwa.googlegroups.com> <43F74956.2060207@comcast.net> <43F79966.3070004@comcast.net> <43F8C006.7030806@comcast.net> <43F95307.5020601@comcast.net> <43FA2370.6050906@comcast.net> <43FA9D68.3060807@comcast.net> Subject: Re: using coax shield to create a loading coil ? Message-ID: Date: Wed, 22 Feb 2006 23:39:17 GMT >> Wherever did you get that idea? A dipole made out of >> 80m hamsticks is less than 1% efficient. > > Well, I guess I should have said: "... do nothing to effect the radiation > efficiency, except possibly reduce it". > > Don't know anything about "Hamsticks", but they must have lousy loading > inductors! > > Frank To be exact; a 16 ft dipole would need to be loaded with inductors of Q = 78 for a 0.99% efficiency. The gain is therefore -18.3 dBi. Frank Article: 221811 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: using coax shield to create a loading coil ? References: <1140274674.116569.208960@g47g2000cwa.googlegroups.com> <43F74956.2060207@comcast.net> <43F79966.3070004@comcast.net> <43F8C006.7030806@comcast.net> <43F95307.5020601@comcast.net> <43FA2370.6050906@comcast.net> <43FA9D68.3060807@comcast.net> Message-ID: <1K7Lf.15962$2O6.11668@newssvr12.news.prodigy.com> Date: Thu, 23 Feb 2006 00:55:25 GMT Frank wrote: > To be exact; a 16 ft dipole would need to be loaded with inductors of Q = 78 > for a 0.99% efficiency. The gain is therefore -18.3 dBi. Sounds about right. Hamsticks are about 12 dB down >from a good screwdriver on 75m. -- 73, Cecil http://www.qsl.net/w5dxp Article: 221812 of rec.radio.amateur.antenna Date: Wed, 22 Feb 2006 21:48:01 -0600 From: Tom Ring Subject: Re: Usenet Kook Alert .... Lyle Blake References: <1140404823.199601.294020@g43g2000cwa.googlegroups.com> <1140541577.324412.146060@g43g2000cwa.googlegroups.com> <1140542227.813378.26820@g14g2000cwa.googlegroups.com> <5mlmv11avigicgfifafdsgejcl3grhsli3@4ax.com> <43FB8752.2010907@wanadoo.nl> <43fba094$0$85254$dbd41001@news.wanadoo.nl> <1140564265.889829.196500@z14g2000cwz.googlegroups.com> <8h8nv1l8i18bk8ajei1jtlub4j5l66hm96@4ax.com> <43fba6d2$0$29574$da0feed9@news.zen.co.uk> Message-ID: <43fd3072$0$7324$39cecf19@news.twtelecom.net> If you don't like top posting, then why do you do it? Personally I think it's much more efficient, You don't have to scroll to the bottom because morons never snip anymore. Ah, the young that have infiltrated the net since we started it all decades ago.... Tom K0TAR DieSea wrote: > RATHER A GOOD IDEA > YOU CAN PUT ME IN YOUR KILL FILE AS WELL > > Not only for SHOUTING but for TOP POSTING AS WELL > > Bye Bye > > DieSea Article: 221813 of rec.radio.amateur.antenna From: "Sal M. Onella" References: Subject: Re: ?? anyone have plans on how to build a usb gps antenna for laptop Message-ID: Date: Wed, 22 Feb 2006 20:55:48 -0800 "Lee" wrote in message news:rXUKf.31812$Q22.24541@fe1.news.blueyonder.co.uk... > > "Sal M. Onella" wrote in message > news:RUSKf.130$Uc2.57@fed1read04... > > > > wrote in message > > news:IyQKf.18144$Ug4.11471@dukeread12... > > > > > > > > > > > http://64.71.184.220/eng/gpspatch.txt > > > > http://www.arrl.org/tis/info/pdf/0210036.pdf > > > > http://vancouver-webpages.com/peter/gpspatch.gif > > Any more designs to suit a Garmin 310 ??? > > Lee .....G6ZSG..... > > Lee, These are free-space antennas, intended for fitting with a length of coax terminated in the particular connector that mates with the connector on your GPS rcvr. My Garmin GPS-III takes a BNC and I have my patch antenna mounted on my van's luggage rack; Eight feet of coax brings the signal inside. Not familiar with the 310 -- are you looking for an add-on antenna that physically mounts to your 310? ... or does the 310 require a special coupling technique (non-connector)? John KD6VKW Article: 221814 of rec.radio.amateur.antenna From: "Sal M. Onella" References: <1140420029.713791.128680@g47g2000cwa.googlegroups.com> Subject: Re: Low power 5w FM Transmitter antenna Message-ID: Date: Wed, 22 Feb 2006 21:11:54 -0800 "Amos Keag" wrote in message news:n7idnenb3-T_IGHenZ2dnUVZ_sSdnZ2d@comcast.com... > 5W will go to the moon!!! > > Bill Turner wrote: > > > ORIGINAL MESSAGE: > > > > Sal M. Onella wrote: > > > > > >>First, 5W will likely go out 5 miles. > > > > > > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > Better than that, 5w will go to the horizon and slightly beyond. On HF, > > I have worked China with 5 watts. > > > > 73, Bill W6WRT > Yeah, I just wanted to put some "overkill perspective" on his 5-watter. Some folks equate RF power with an equivalent light bulb and it's just not a good comparison. I regularly work to near the horizon on a watt or two (VHF). The QRP record I've heard is 1/40 W from North America to Australia (CW). 73, John, KD6VKW Article: 221815 of rec.radio.amateur.antenna From: Owen Duffy Subject: Re: Low power 5w FM Transmitter antenna Message-ID: References: <1140420029.713791.128680@g47g2000cwa.googlegroups.com> Date: Thu, 23 Feb 2006 05:29:02 GMT On Wed, 22 Feb 2006 21:11:54 -0800, "Sal M. Onella" wrote: >Yeah, I just wanted to put some "overkill perspective" on his 5-watter. >Some folks equate RF power with an equivalent light bulb and it's just >not a good comparison. Let him go... the scenario probably goes like this: He runs 5W out on the farm, it can be heard in town, someone passes the word around about the cool music on pirate radio, the operators of the commercial stations hear about it and feel agrieved (loss of audience, ratings, revenue), the regulator is called in. Breaches of Radiocommunications Act and Copyright Act to name just a couple. -- Article: 221816 of rec.radio.amateur.antenna From: "Sal M. Onella" References: <1140420029.713791.128680@g47g2000cwa.googlegroups.com> Subject: Re: Low power 5w FM Transmitter antenna Message-ID: Date: Wed, 22 Feb 2006 21:37:01 -0800 "Owen Duffy" wrote in message news:jkhqv1l99bd3p2eo2gpm851hhat5sbu28h@4ax.com... > On Wed, 22 Feb 2006 21:11:54 -0800, "Sal M. Onella" > wrote: > > > >Yeah, I just wanted to put some "overkill perspective" on his 5-watter. > >Some folks equate RF power with an equivalent light bulb and it's just > >not a good comparison. > > Let him go... the scenario probably goes like this: > > He runs 5W out on the farm, it can be heard in town, someone passes > the word around about the cool music on pirate radio, the operators of > the commercial stations hear about it and feel agrieved (loss of > audience, ratings, revenue), the regulator is called in. > > Breaches of Radiocommunications Act and Copyright Act to name just a > couple. > > -- Yup, could be. Article: 221817 of rec.radio.amateur.antenna From: Dot Subject: Re: using coax shield to create a loading coil ? Message-ID: <2ikqv15uhv607je0gamim4mgaqcnq61p7o@4ax.com> References: <43F8C006.7030806@comcast.net> <43F95307.5020601@comcast.net> <43FA2370.6050906@comcast.net> <43FA9D68.3060807@comcast.net> <1K7Lf.15962$2O6.11668@newssvr12.news.prodigy.com> Date: Thu, 23 Feb 2006 01:12:41 -0500 On Thu, 23 Feb 2006 04:50:27 GMT, "Frank" wrote: >I wonder what the efficiency of a Miracle Whip is? Mixed with tuna and served with a pickle... about 35%. Article: 221818 of rec.radio.amateur.antenna From: Dot Subject: Re: nec simulation - unexpected result ?? Message-ID: References: <43F95307.5020601@comcast.net> <43FA2370.6050906@comcast.net> <43FA9D68.3060807@comcast.net> <1K7Lf.15962$2O6.11668@newssvr12.news.prodigy.com> <43FD4A4F.9010209@comcast.net> Date: Thu, 23 Feb 2006 01:35:37 -0500 On Wed, 22 Feb 2006 21:38:23 -0800, dansawyeror wrote: >Is there an explanation for this? The first resonance is at 1/4 wavelength, not half. A quarter wave whip above a sufficient untuned groundplane (eg. a car) is a resonant antenna. Low impedance resonances occur every odd multiple (1, 3, 5, etc.) of a quarter wavelength. These are current fed antennas. High impedance resonances occur every even multiple (2, 4, 6...) of a quarter wavelength. These are voltage fed antennas. A dipole is actually 2 resonant antennas driven from a common source. Each half of the dipole has to be resonant to make the overall antenna resonant. It matters not how each element is made resonant and they need not be identical. If each half of the dipole is resonant on it's own, the overall dipole will also be resonant. But, all that said, let me remind you that resonance isn't the be all and end all of antenna design... some spot-on resonant antennas don't radiate a signal worth squat. Resonance is also of little value if the impedance is not workable with your transmitter. And then there's the little matter of radiation patterns. Article: 221819 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: nec simulation - unexpected result ?? References: <1140274674.116569.208960@g47g2000cwa.googlegroups.com> <43F74956.2060207@comcast.net> <43F79966.3070004@comcast.net> <43F8C006.7030806@comcast.net> <43F95307.5020601@comcast.net> <43FA2370.6050906@comcast.net> <43FA9D68.3060807@comcast.net> <1K7Lf.15962$2O6.11668@newssvr12.news.prodigy.com> <43FD4A4F.9010209@comcast.net> Message-ID: Date: Thu, 23 Feb 2006 12:27:00 GMT dansawyeror wrote: > I have been experimenting with various loaded antennas to use in my > relatively limited space. For this I assumed the two arms of a dipole > must be identical to support resonance, this assumption has not been > supported by modeling. Is there an explanation for this? An electrical 1/2 wavelength conductor is resonant no matter where you feed it. Even if you don't feed it anywhere, it is still resonant. -- 73, Cecil http://www.qsl.net/w5dxp Article: 221820 of rec.radio.amateur.antenna From: "Alan" Subject: Big push for the government to sell more airways... Message-ID: <0hkLf.32135$no3.215@tornado.southeast.rr.com> Date: Thu, 23 Feb 2006 15:11:56 GMT At least the opinions of the techie CEO's aren't siding with BPL proponents....http://today.reuters.com/news/newsArticle.aspx?type=technology News&storyID=2006-02-23T023921Z_01_N22224784_RTRUKOC_0_US-TELECOMS-WIRELESS- CEOS.xml Alan -- Windsurfing Club: http://www.ibscc.org Article: 221821 of rec.radio.amateur.antenna Message-ID: <313030303837383543FD61ED21@zetnet.co.uk> Date: Thu, 23 Feb 2006 07:19:09 GMT From: Dave Piggin Subject: Re: Connectors References: <313030303837383543FB79CE79@zetnet.co.uk> Yup! It's not a "might"... PL-259 (male) mates with the SO-239 (female) 73, K9DCI Dyslexic fingers!!!! You are correct Sir and I stand corrected. d;-(( Just hope it explained it in plain English to the originator of the thread. Dave -- 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: 221822 of rec.radio.amateur.antenna From: "Frank" References: <1140274674.116569.208960@g47g2000cwa.googlegroups.com> <43F74956.2060207@comcast.net> <43F79966.3070004@comcast.net> <43F8C006.7030806@comcast.net> <43F95307.5020601@comcast.net> <43FA2370.6050906@comcast.net> <43FA9D68.3060807@comcast.net> <1K7Lf.15962$2O6.11668@newssvr12.news.prodigy.com> <43FD4A4F.9010209@comcast.net> Subject: Re: nec simulation - unexpected result ?? Message-ID: <4wkLf.4207$vC4.1279@clgrps12> Date: Thu, 23 Feb 2006 15:28:00 GMT "dansawyeror" wrote in message news:43FD4A4F.9010209@comcast.net... > All, > > I have been experimenting with various loaded antennas to use in my > relatively limited space. For this I assumed the two arms of a dipole must > be identical to support resonance, this assumption has not been supported > by modeling. > > Actual model runs show that if the two arms of a dipole are close then > there is sufficient interaction that they will combine to form a single > resonance. The model below shows a simple example of this. The loads and > length of the arms are not equal, however nec predicts a single resonance > at about 3.5 MHz. Changes of 10 to 20 percent around resonance seem to > create one resonance. > > Is there an explanation for this? > > Thanks - Dan kb0qil No matter what Dan, you should see only one resonance at the overall length of a half wave. Not that resonance has any bearing on antenna efficiency. Also; your NEC model has uneven segmentation, which does produce significant errors. Interesting to note that your antenna is also resonant at 7 MHz. 73, Frank Article: 221823 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: nec simulation - unexpected result ?? Date: Thu, 23 Feb 2006 14:59:36 -0600 Message-ID: <25869-43FE2238-253@storefull-3253.bay.webtv.net> References: Dot wrote: "Low impedance resonances occur every odd multiple (1,3,5, etc.) of a quarter wavelength." As I read from Arnold B. Bailey, he takes the opposite view. I think a 1/4-wavelength folded dipole shares some characteristics with a short-circuited 1/4-wavelength stub; short on one end, high impedance on the other end. Therefore, I agree with Bailey. Arnold B. Bailey shows interest in folded dipoles in "TV ans Other Receiving Antennas", He catalogs the first through the eighth resonances on page 410. The odd order (1,3,5, etc.) resonances present high drivepoint impedances. Even order resonances present low drivepoint impedances. Page 509 is Bailey`s catalog page for the 1/4-wave folded dipole. With a 1/4-in dia rod spaced at 1 inch between sides at 200 MHz, the antenna has a 6000-ohm drivepoint. Cecil says this is too good to be true because a 1/4-wave-matching-section of 600-ohm line would match the 1/4-wave dipole to 50 ohms. Page 510 is Bailey`s catalog page for the 1/2-wave folded dipole. It has 0 dBd gain and its pattern is the same as a straight dipole. Same as the 1/4-wave folded dipole too for practical purposes. The 1/4-wave folded dipole has only a 1/2 dB less gain than the 1/2-wave folded dipole, but its resonance is sharper. It has only 5% bandwidth versus 45% for the 1/2-wave folded dipole. This can be an advantage if it prevents receiver overload when using the 1/4-wave folded dipole. Best regards, Richard Harrison, KB5WZI Article: 221824 of rec.radio.amateur.antenna From: "Phil" References: <1140659045.271910.271190@g47g2000cwa.googlegroups.com> Subject: Re: 300 ohm folded dipole from ARRL Handbook, early 1990's Message-ID: Date: Thu, 23 Feb 2006 21:05:20 GMT wrote in message news:1140659045.271910.271190@g47g2000cwa.googlegroups.com... > Have you experience running 100w into one of these transformers > yourself? I kinda doubt they would take any watts. > > If I understand you correctly you are talking about the little unit > that connects the cable to the old 300ohm input of 1970s type tv. > These units have very small toroids, only maybe a quarter inch in > diameter, that are designed for microvolts of excitation at the bottom > end of TV band - which is somewhere near say 50Mhz. They will not > handle any magnitizing flux and I would bet a watt at 20m would > overheat it. > > regards, > Bob > N9NEO > Those VHF 75/300 ohms transformers where designed for the 48 to 300 MHz VHF TV-segment. The neosid core is not that small: it just covers my thumbnail. It indeed can handle 100 watts on 14 MHz. I tested it thoroughly: a friend had taken his transceiver to Costa Rica where he was visiting family and I wanted to raise an antenna very quickly to stay in touch with him. I suspended a folded dipole under the roof of my house and used the described VHF bal/un to feed it. We had (almost) daily skeds on 14 MHz. The "almost" was not due to propagation but had more to do with the fact that the electricity plant was only up 3 or 4 days a week in Costa Rica at that time. Later I used the same bal/un with a folded dipole for the 20 m band made with twin lead. I never used it on lower frequencies. I am sure that it would get pretty hot with 100 watts on 80 m. Kind regards, Phil Article: 221825 of rec.radio.amateur.antenna From: Dot Subject: Re: nec simulation - unexpected result ?? Message-ID: References: <25869-43FE2238-253@storefull-3253.bay.webtv.net> Date: Thu, 23 Feb 2006 18:59:37 -0500 On Thu, 23 Feb 2006 14:59:36 -0600, richardharrison@webtv.net (Richard Harrison) wrote: >Dot wrote: >"Low impedance resonances occur every odd multiple (1,3,5, etc.) of a >quarter wavelength." > >As I read from Arnold B. Bailey, he takes the opposite view. I think a >1/4-wavelength folded dipole shares some characteristics with a >short-circuited 1/4-wavelength stub; short on one end, high impedance on >the other end. Therefore, I agree with Bailey. I wasn't talking about a "1/4 wave folded dipole" ... I was talking about a piece of wire of a given length. Article: 221826 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: nec simulation - unexpected result ?? References: <25869-43FE2238-253@storefull-3253.bay.webtv.net> Message-ID: Date: Fri, 24 Feb 2006 01:14:24 GMT Dot wrote: > I wasn't talking about a "1/4 wave folded dipole" ... > I was talking about a piece of wire of a given length. A 1/4 wavelength piece of wire in free space is resonant at half that wavelength. :-) -- 73, Cecil http://www.qsl.net/w5dxp Article: 221827 of rec.radio.amateur.antenna Message-ID: <43FEA96C.8C680EBE@cj.org> From: chuck Subject: Re: Looking for aluminum tubing/rod in DC/MD area References: <1140474918.828207.324820@g14g2000cwa.googlegroups.com> <43FB2F8D.A7725602@nospam.com> Date: Fri, 24 Feb 2006 06:36:28 GMT hi, I have also used this company, martin is good to deal with, he cuts the tubing any length you like, as long as it is 6 ft or less, it can ship priority mail. he has all the good stuff, 6061 6063 nice. chuck Gloria wrote: > Hi, > > I know you asked for a local source, > I have used this guy on ebay stores, > his pricing is very good and he ships > us priority mail with tracking. > > http://stores.ebay.com/TRINITY-METAL-SALES_W0QQsspagenameZFAVQ3aFQ3aSLLRQQtZkm Article: 221828 of rec.radio.amateur.antenna From: "Lee" References: Subject: Re: ?? anyone have plans on how to build a usb gps antenna for laptop Message-ID: Date: Fri, 24 Feb 2006 08:45:30 GMT "Sal M. Onella" wrote in message news:MebLf.968$Uc2.471@fed1read04... > > "Lee" wrote in message > news:rXUKf.31812$Q22.24541@fe1.news.blueyonder.co.uk... > > > > "Sal M. Onella" wrote in message > > news:RUSKf.130$Uc2.57@fed1read04... > > > > > > wrote in message > > > news:IyQKf.18144$Ug4.11471@dukeread12... > > > > > > > > > > > > > > > http://64.71.184.220/eng/gpspatch.txt > > > > > > http://www.arrl.org/tis/info/pdf/0210036.pdf > > > > > > http://vancouver-webpages.com/peter/gpspatch.gif > > > > Any more designs to suit a Garmin 310 ??? > > > > Lee .....G6ZSG..... > > > > > > Lee, > > These are free-space antennas, intended for fitting with a length of coax > terminated in the particular connector that mates with the connector on your > GPS rcvr. My Garmin GPS-III takes a BNC and I have my patch antenna mounted > on my van's luggage rack; Eight feet of coax brings the signal inside. Not too sure what i want, i`m a bit of a newb to GPS....just bought it!!!... > Not familiar with the 310 -- are you looking for an add-on antenna that > physically mounts to your 310? ... or does the 310 require a special > coupling technique (non-connector)? Same as the 320,330 and 340 series Lee.......G6ZSG....... Article: 221829 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: nec simulation - unexpected result ?? Date: Fri, 24 Feb 2006 07:44:56 -0600 Message-ID: <15631-43FF0DD8-401@storefull-3255.bay.webtv.net> References: Amos Keag wrote: "But, what does feedpoint impedance have to do with resonance?" Imagine a whip worked against ground. It is resonant at 1/4-wavelength where it presents a low impedance. It is resonant again at 1/2-wavelength where it presents a high impedance. Best regards, Richard Harrison, KB5WZI Article: 221830 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: nec simulation - unexpected result ?? References: <1140274674.116569.208960@g47g2000cwa.googlegroups.com> <43F74956.2060207@comcast.net> <43F79966.3070004@comcast.net> <43F8C006.7030806@comcast.net> <43F95307.5020601@comcast.net> <43FA2370.6050906@comcast.net> <43FA9D68.3060807@comcast.net> <1K7Lf.15962$2O6.11668@newssvr12.news.prodigy.com> <43FD4A4F.9010209@comcast.net> <4wkLf.4207$vC4.1279@clgrps12> <43FE9C4F.3050104@comcast.net> Message-ID: Date: Fri, 24 Feb 2006 13:57:44 GMT dansawyeror wrote: > Simulation predicts the impedance will change when it is not feed at the > center, it appears to go up as the feed point is moved. An off-center-fed dipole will match 300 ohm twin lead if fed at the correct point. This is covered in my 1957 ARRL Handbook. -- 73, Cecil http://www.qsl.net/w5dxp Article: 221831 of rec.radio.amateur.antenna From: Big Endian Subject: Q about balanced feed line Message-ID: Date: Fri, 24 Feb 2006 14:00:11 GMT How does one check the balance between two parallel feed wires into a doublet antenna. Neon bulbs or some sort of meter gizmo? tnx d Article: 221832 of rec.radio.amateur.antenna From: "John, N9JG" Subject: 80 m compact loop - progress report Message-ID: Date: Fri, 24 Feb 2006 16:14:12 GMT This winter I have been working on the design and construction of a compact loop for 80 meters. The loop will be constructed from 72 ft of 3/4 in copper pipe and will be in the shape of an octagon. The plane of the loop will be vertical, and the loop will be remotely tuned by a vacuum variable capacitor coupled to a geared stepper motor. I have just finished constructing and testing the driver for the stepper motor. See http://tinyurl.com/bwobb for pictures and some information about the system. Constructive comments will be appreciated. John, N9JG Article: 221833 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Q about balanced feed line Date: Fri, 24 Feb 2006 08:24:10 -0800 Message-ID: <11vucpb76cj4206@corp.supernews.com> References: That topic was discussed in some detail on this newsgroup just a few weeks ago. Do a search in groups.google.com of this newsgroup for the topic "unbalance indicator". Roy Lewallen, W7EL Big Endian wrote: > How does one check the balance between two parallel feed wires into a > doublet antenna. Neon bulbs or some sort of meter gizmo? > > tnx > > d Article: 221834 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: Q about balanced feed line Date: Fri, 24 Feb 2006 16:38:01 +0000 (UTC) Message-ID: References: > How does one check the balance between two parallel feed wires into a > doublet antenna. =========================================== Just go out into the garden and look up at the antenna. If each half of the doublet is of about the same length, and both halves are about the same height above ground, then the parallel pair of wires are balanced. ---- Reg. Article: 221835 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Q about balanced feed line Date: Fri, 24 Feb 2006 09:32:25 -0800 Message-ID: <11vugpalqdcltd4@corp.supernews.com> References: Amos Keag wrote: > > YEP!! > > An RF Ammeter will do just fine Balance requires that the currents in the two wires be equal in magnitude and opposite in phase (or direction). How do you connect an RF ammeter to determine this? Roy Lewallen, W7EL Article: 221836 of rec.radio.amateur.antenna From: chuck Subject: Re: Q about balanced feed line References: <11vugpalqdcltd4@corp.supernews.com> Message-ID: <7zHLf.2661$F56.1750@newsread3.news.atl.earthlink.net> Date: Fri, 24 Feb 2006 17:41:23 GMT Wouldn't the clamp-on type ammeter as discussed previously provide that information (provided a section of twin lead small enough to fit the clamp were used? Chuck Roy Lewallen wrote: > Amos Keag wrote: > >> >> YEP!! >> >> An RF Ammeter will do just fine > > > Balance requires that the currents in the two wires be equal in > magnitude and opposite in phase (or direction). How do you connect an RF > ammeter to determine this? > > Roy Lewallen, W7EL Article: 221837 of rec.radio.amateur.antenna From: The Benevolent dbu Subject: Re: Q about balanced feed line References: <11vucpb76cj4206@corp.supernews.com> Message-ID: Date: Fri, 24 Feb 2006 17:55:22 GMT In article <11vucpb76cj4206@corp.supernews.com>, Roy Lewallen wrote: > That topic was discussed in some detail on this newsgroup just a few > weeks ago. Do a search in groups.google.com of this newsgroup for the > topic "unbalance indicator". > > Roy Lewallen, W7EL Will do. Thanks Roy > > Big Endian wrote: > > How does one check the balance between two parallel feed wires into a > > doublet antenna. Neon bulbs or some sort of meter gizmo? > > > > tnx > > > > d -- "Welcome to President Clinton, Mrs. Clinton, and my fellow astronauts." Al Gore Article: 221838 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: Q about balanced feed line Date: Fri, 24 Feb 2006 18:11:03 +0000 (UTC) Message-ID: References: <11vugpalqdcltd4@corp.supernews.com> "Roy Lewallen" wrote > Balance requires that the currents in the two wires be equal in > magnitude and opposite in phase (or direction). How do you connect an RF > ammeter to determine this? ===================================== It's unbelievably easy Roy, you just pass both wires together through a clamp-on ammeter. ---- Reg. Article: 221839 of rec.radio.amateur.antenna From: "AAA RF Products" Subject: FS: Coax Connectors, Adapters & Cable assemblies @ great prices Message-ID: Date: Fri, 24 Feb 2006 11:25:00 -0800 For your free copy of our new catalog, Please email sales@AAARFProducts.com or see www.aaarfproducts.com or call 949 481 3154 (San Clemente, CA, USA) No minimum order. No handling charges Article: 221840 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: nec simulation - unexpected result ?? References: <1140274674.116569.208960@g47g2000cwa.googlegroups.com> <43F74956.2060207@comcast.net> <43F79966.3070004@comcast.net> <43F8C006.7030806@comcast.net> <43F95307.5020601@comcast.net> <43FA2370.6050906@comcast.net> <43FA9D68.3060807@comcast.net> <1K7Lf.15962$2O6.11668@newssvr12.news.prodigy.com> <43FD4A4F.9010209@comcast.net> <4wkLf.4207$vC4.1279@clgrps12> <43FE9C4F.3050104@comcast.net> Message-ID: Date: Fri, 24 Feb 2006 19:28:37 GMT Amos Keag wrote: > But, what does feedpoint impedance have to do with > resonance? On a standing wave antenna, like a center-fed dipole, the feedpoint impedance is (Vfor+Vref)/(Ifor+Iref) where Vfor is forward voltage, Vref is reflected voltage, etc. and the plus sign denotes superposition, i.e. phasor addition. On a wire dipole, the resonant feedpoint impedance will occur only when all the phases line up, i.e. If Vfor is at zero degrees, Vref must be at 180 degrees, Ifor must be at zero degrees, and Iref must be at zero degrees. That way, we get minimum voltage divided by maximum current with a resultant phase angle of zero degrees. Eureka! The dipole is resonant because the feedpoint impedance is purely resistive. -- 73, Cecil http://www.qsl.net/w5dxp Article: 221841 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Q about balanced feed line References: Message-ID: Date: Fri, 24 Feb 2006 19:37:24 GMT Big Endian wrote: > How does one check the balance between two parallel feed wires into a > doublet antenna. Neon bulbs or some sort of meter gizmo? The easiest way is to use a large sampling toroid such that the balanced line can be fed through the toroid. A ten-turn sampling coil will indicate any unbalance. Note that the balanced line needs to be centered with respect to the toroid and needs to be moved along the feedline to obtain maximum accuracy. Ideally, the toroid needs to be located at a standing wave current maximum point. Since my choke-balun is always located at a current maximum point, I can easily monitor my feedline balance. You can also use smaller toroids on each line and then superpose the two readings. But the two toroids need to be identical which is no small requirement. -- 73, Cecil http://www.qsl.net/w5dxp Article: 221842 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Q about balanced feed line References: Message-ID: Date: Fri, 24 Feb 2006 19:39:31 GMT Reg Edwards wrote: > If each half of the doublet is of about the same length, and both > halves are about the same height above ground, then the parallel pair > of wires are balanced. What if one is broken and you don't know it? -- 73, Cecil http://www.qsl.net/w5dxp Article: 221843 of rec.radio.amateur.antenna From: Owen Duffy Subject: Re: nec simulation - unexpected result ?? Message-ID: References: <43FA9D68.3060807@comcast.net> <1K7Lf.15962$2O6.11668@newssvr12.news.prodigy.com> <43FD4A4F.9010209@comcast.net> <4wkLf.4207$vC4.1279@clgrps12> <43FE9C4F.3050104@comcast.net> Date: Fri, 24 Feb 2006 19:45:28 GMT On Fri, 24 Feb 2006 19:28:37 GMT, Cecil Moore wrote: >Amos Keag wrote: >> But, what does feedpoint impedance have to do with >> resonance? > >On a standing wave antenna, like a center-fed dipole, the >feedpoint impedance is (Vfor+Vref)/(Ifor+Iref) where Vfor >is forward voltage, Vref is reflected voltage, etc. and >the plus sign denotes superposition, i.e. phasor addition. > >On a wire dipole, the resonant feedpoint impedance will >occur only when all the phases line up, i.e. If Vfor is >at zero degrees, Vref must be at 180 degrees, Ifor must >be at zero degrees, and Iref must be at zero degrees. That >way, we get minimum voltage divided by maximum current with >a resultant phase angle of zero degrees. Eureka! The dipole >is resonant because the feedpoint impedance is purely >resistive. Cecil, are you saying that a resonant dipole must have a low impedance, and that modes where the feedpoint impedance is purely resistive but high are not "resonant"? That seems to be what your formulae above and explanation suggests. Owen -- Article: 221844 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: nec simulation - unexpected result ?? References: <15631-43FF0DD8-401@storefull-3255.bay.webtv.net> Message-ID: Date: Fri, 24 Feb 2006 19:53:53 GMT Amos Keag wrote: > Resonance has NOTHING to do with impedance. jX is only zero at resonance. -- 73, Cecil http://www.qsl.net/w5dxp Article: 221845 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Q about balanced feed line References: Message-ID: Date: Fri, 24 Feb 2006 19:55:20 GMT Amos Keag wrote: > An RF Ammeter will do just fine What if the first current is one amp at zero degrees and the other current is one amp at 45 degrees. Is that balanced? -- 73, Cecil http://www.qsl.net/w5dxp Article: 221846 of rec.radio.amateur.antenna From: Dot Subject: Re: Q about balanced feed line Message-ID: <0epuv1lpbqi5adut9qo1ijkp5k38hro11k@4ax.com> References: Date: Fri, 24 Feb 2006 15:01:46 -0500 On Fri, 24 Feb 2006 19:39:31 GMT, Cecil Moore wrote: >What if one is broken and you don't know it? I one side of a dipole gets loose, you'll know all about it... the swr is likely to go to 6 or higher. Your receiver would be mysteriously quiet and you wouldn't be getting normal power from your transmitter. In the worst case it could damage your equipment. Antenna failure is not trivial. Article: 221847 of rec.radio.amateur.antenna From: "Frank's" References: Subject: Re: 80 m compact loop - progress report Message-ID: <4WJLf.1213$dg.9@clgrps13> Date: Fri, 24 Feb 2006 20:22:24 GMT "John, N9JG" wrote in message news:ohGLf.796098$_o.157184@attbi_s71... > This winter I have been working on the design and construction of a > compact loop for 80 meters. The loop will be constructed from 72 ft of 3/4 > in copper pipe and will be in the shape of an octagon. The plane of the > loop will be vertical, and the loop will be remotely tuned by a vacuum > variable capacitor coupled to a geared stepper motor. > > I have just finished constructing and testing the driver for the stepper > motor. See > http://tinyurl.com/bwobb for pictures and some information about the > system. Constructive comments will be appreciated. > > John, N9JG John, how high above ground is the antenna? Frank, VE6CB Article: 221848 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: nec simulation - unexpected result ?? References: <43FA9D68.3060807@comcast.net> <1K7Lf.15962$2O6.11668@newssvr12.news.prodigy.com> <43FD4A4F.9010209@comcast.net> <4wkLf.4207$vC4.1279@clgrps12> <43FE9C4F.3050104@comcast.net> Message-ID: <%lKLf.39590$H71.27479@newssvr13.news.prodigy.com> Date: Fri, 24 Feb 2006 20:52:11 GMT Owen Duffy wrote: > Cecil, are you saying that a resonant dipole must have a low > impedance, and that modes where the feedpoint impedance is purely > resistive but high are not "resonant"? That seems to be what your > formulae above and explanation suggests. Yes Owen, that's what I am saying. When I was at Texas A&M in the dark ages, we called the feedpoint impedance of a one- wavelength dipole an "anti-resonant" impedance. It is explained at: http://dx.doi.org/10.1036/1097-8542.041800 "Antiresonance - The condition for which the impedance of a given electric ... system is very high, approaching infinity." Semantics strikes again. To distinguish the left-most low resistance point on an SWR circle from the right-most high resistance point, we mid-20th-century Aggie EEs called the leftmost point, "resonant", and called the rightmost point, "anti-resonant". If you and I were ever to agree on definitions, I have no doubt that we would also agree on concepts. -- 73, Cecil http://www.qsl.net/w5dxp Article: 221849 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Q about balanced feed line References: <0epuv1lpbqi5adut9qo1ijkp5k38hro11k@4ax.com> Message-ID: Date: Fri, 24 Feb 2006 20:54:41 GMT Dot wrote: > I one side of a dipole gets loose, you'll know all about it... the swr is > likely to go to 6 or higher. Your receiver would be mysteriously quiet and > you wouldn't be getting normal power from your transmitter. In the worst > case it could damage your equipment. Would you believe that an SGC-230 will match that mismatch condition and the only clue that you will have is that you are not making as many contacts as before? -- 73, Cecil http://www.qsl.net/w5dxp Article: 221850 of rec.radio.amateur.antenna From: Owen Duffy Subject: Re: nec simulation - unexpected result ?? Message-ID: References: <1K7Lf.15962$2O6.11668@newssvr12.news.prodigy.com> <43FD4A4F.9010209@comcast.net> <4wkLf.4207$vC4.1279@clgrps12> <43FE9C4F.3050104@comcast.net> <%lKLf.39590$H71.27479@newssvr13.news.prodigy.com> Date: Fri, 24 Feb 2006 21:27:08 GMT On Fri, 24 Feb 2006 20:52:11 GMT, Cecil Moore wrote: >Semantics strikes again. To distinguish the left-most low resistance >point on an SWR circle from the right-most high resistance point, we >mid-20th-century Aggie EEs called the leftmost point, "resonant", and >called the rightmost point, "anti-resonant". > >If you and I were ever to agree on definitions, I have no doubt >that we would also agree on concepts. I am sure we are talking the meaning of the terms (semantics) rather than the underlying concept. Narrowing the term resonance to only apply to the resonance that exhibits a series resonance equivalent behaviour seems to me to unnecessarily limit the meaning of resonance (though I note it is used in optics to some extent). I think of the high impedance of a dipole with zero reactance at some frequencies also as a resonance, and I think you did too when you said recently to Amos "jX is only zero at resonance." If that is to mean that jX is "only ever" zero at resonance, then if jX is zero, you have resonance, whether R is high or low. On that basis, one would have to say that a full wave centre fed dipole exhibits (at the feed point) resonance similar to a lossy parallel tuned circuit and should be considered a resonant radiator. Owen -- Article: 221851 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Q about balanced feed line Date: Fri, 24 Feb 2006 13:29:48 -0800 Message-ID: <11vuumdqpkgat09@corp.supernews.com> References: <11vugpalqdcltd4@corp.supernews.com> <7zHLf.2661$F56.1750@newsread3.news.atl.earthlink.net> Sorry, when I read "RF ammeter", I thought only of the old type which resembles a panel meter and has two terminals to connect in line with a single conductor. A clamp-on type would indeed do the job, as we discussed here not long ago. Roy Lewallen, W7EL chuck wrote: > Wouldn't the clamp-on type ammeter as discussed previously provide that > information (provided a section of twin lead small enough to fit the > clamp were used? > > Chuck > > Roy Lewallen wrote: >> Amos Keag wrote: >> >>> >>> YEP!! >>> >>> An RF Ammeter will do just fine >> >> >> Balance requires that the currents in the two wires be equal in >> magnitude and opposite in phase (or direction). How do you connect an >> RF ammeter to determine this? >> >> Roy Lewallen, W7EL Article: 221852 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: nec simulation - unexpected result ?? Date: Fri, 24 Feb 2006 13:36:51 -0800 Message-ID: <11vuv3l7thdn87@corp.supernews.com> References: <15631-43FF0DD8-401@storefull-3255.bay.webtv.net> Amos Keag wrote: > > Resonance has NOTHING to do with impedance. Resonance is resonance; it > has a harmonic response. > . . . Resonance has everything to do with impedance. Resonance is defined as any frequency at which the impedance is purely resistive; that is, where the reactive part of the impedance is zero. And that is all resonance is. You can change the resonant frequency of an antenna by simply adding a series or parallel inductor or capacitor at the feedpoint. This doesn't change the antenna characteristics in any other way than to alter the feedpoint impedance. Roy Lewallen, W7EL Article: 221853 of rec.radio.amateur.antenna From: Dot Subject: Re: Q about balanced feed line Message-ID: <22uuv1lofv5vcri03nnk30ppc4s779bbth@4ax.com> References: <0epuv1lpbqi5adut9qo1ijkp5k38hro11k@4ax.com> Date: Fri, 24 Feb 2006 16:20:16 -0500 On Fri, 24 Feb 2006 20:54:41 GMT, Cecil Moore wrote: >Dot wrote: >> I one side of a dipole gets loose, you'll know all about it... the swr is >> likely to go to 6 or higher. Your receiver would be mysteriously quiet and >> you wouldn't be getting normal power from your transmitter. In the worst >> case it could damage your equipment. > >Would you believe that an SGC-230 will match that mismatch >condition and the only clue that you will have is that you >are not making as many contacts as before? Which, of course, explains my continuing reluctance to use transmatches. Yes it limits my range of antenna usage (and experience) but curse it all, I'd really like to know when something goes wrong. Article: 221854 of rec.radio.amateur.antenna From: "John, N9JG" References: <4WJLf.1213$dg.9@clgrps13> Subject: Re: 80 m compact loop - progress report Message-ID: Date: Fri, 24 Feb 2006 21:40:59 GMT Initially, at least, the loop will be just high enough so that a lawnmower can get underneath the lowest side of the octagon. It the loop works fairly well, I might install a 40 foot fiberglass flagpole and suspend the top of the loop from the top of the flagpole. Supposedly, that might cut down on some loss due to ground currents. "Frank's" wrote in message news:4WJLf.1213$dg.9@clgrps13... > "John, N9JG" wrote in message > news:ohGLf.796098$_o.157184@attbi_s71... >> This winter I have been working on the design and construction of a >> compact loop for 80 meters. The loop will be constructed from 72 ft of >> 3/4 in copper pipe and will be in the shape of an octagon. The plane of >> the loop will be vertical, and the loop will be remotely tuned by a >> vacuum variable capacitor coupled to a geared stepper motor. >> >> I have just finished constructing and testing the driver for the stepper >> motor. See >> http://tinyurl.com/bwobb for pictures and some information about the >> system. Constructive comments will be appreciated. >> >> John, N9JG > > John, how high above ground is the antenna? > > Frank, VE6CB > Article: 221855 of rec.radio.amateur.antenna From: "Frank's" References: <4WJLf.1213$dg.9@clgrps13> Subject: Re: 80 m compact loop - progress report Message-ID: Date: Fri, 24 Feb 2006 21:42:47 GMT >> This winter I have been working on the design and construction of a >> compact loop for 80 meters. The loop will be constructed from 72 ft of >> 3/4 in copper pipe and will be in the shape of an octagon. The plane of >> the loop will be vertical, and the loop will be remotely tuned by a >> vacuum variable capacitor coupled to a geared stepper motor. >> >> I have just finished constructing and testing the driver for the stepper >> motor. See >> http://tinyurl.com/bwobb for pictures and some information about the >> system. Constructive comments will be appreciated. >> >> John, N9JG > > John, how high above ground is the antenna? > > Frank, VE6CB John, just for interest I placed the top of the antenna at 30 ft; which puts the base at about 8' 3". Using NEC's Sommerfeld/Norton ground with: sigma = 5 mS/m, and Er = 13. The input impedance computes to 6.57 + j855.6 ohms. Since this is very close to the edge of the Smith Chart, your 1 ohm figure is probably within a reasonable margin of error. However I cannot see how you can match such an impedance with a single element. The structure appears to be a very efficient, physically small, antenna. NEC computes 0.84% copper loss. Frank Article: 221856 of rec.radio.amateur.antenna From: Big Endian Subject: Re: Q about balanced feed line References: Message-ID: Date: Fri, 24 Feb 2006 21:44:15 GMT In article , Cecil Moore wrote: > Big Endian wrote: > > How does one check the balance between two parallel feed wires into a > > doublet antenna. Neon bulbs or some sort of meter gizmo? > > The easiest way is to use a large sampling toroid such > that the balanced line can be fed through the toroid. > A ten-turn sampling coil will indicate any unbalance. > Note that the balanced line needs to be centered with > respect to the toroid and needs to be moved along the > feedline to obtain maximum accuracy. Ideally, the toroid > needs to be located at a standing wave current maximum > point. Since my choke-balun is always located at a current > maximum point, I can easily monitor my feedline balance. > > You can also use smaller toroids on each line and then > superpose the two readings. But the two toroids need to > be identical which is no small requirement. An unbalanced condition would have a meter indication, like current flow? Balanced the meter needle would not move? I want to monitor this condition on the feedline in the shack from the Johnson KW matchbox. Article: 221857 of rec.radio.amateur.antenna From: "Frank's" References: <4WJLf.1213$dg.9@clgrps13> Subject: Re: 80 m compact loop - progress report Message-ID: Date: Fri, 24 Feb 2006 21:45:42 GMT "John, N9JG" wrote in message news:L3LLf.796414$_o.66941@attbi_s71... > Initially, at least, the loop will be just high enough so that a lawnmower > can get underneath the lowest side of the octagon. It the loop works > fairly well, I might install a 40 foot fiberglass flagpole and suspend the > top of the loop from the top of the flagpole. Supposedly, that might cut > down on some loss due to ground currents. Thanks John, I guess my estimate of 8ft at the base is a bit high -- see following post. Frank Article: 221858 of rec.radio.amateur.antenna From: "John, N9JG" References: <4WJLf.1213$dg.9@clgrps13> Subject: Re: 80 m compact loop - progress report Message-ID: Date: Fri, 24 Feb 2006 21:54:29 GMT I plan to feed the loop at the side opposite to the side containing the tuning capacitor. Note that the capacitor is inserted in series with the loop and is used to tune the loop to resonance at the operating frequency. A gamma match is used to connect the coax to the loop, and the loop is NOT cut on the feed side. "Frank's" wrote in message news:r5LLf.1227$dg.71@clgrps13... >>> This winter I have been working on the design and construction of a >>> compact loop for 80 meters. The loop will be constructed from 72 ft of >>> 3/4 in copper pipe and will be in the shape of an octagon. The plane of >>> the loop will be vertical, and the loop will be remotely tuned by a >>> vacuum variable capacitor coupled to a geared stepper motor. >>> >>> I have just finished constructing and testing the driver for the stepper >>> motor. See >>> http://tinyurl.com/bwobb for pictures and some information about the >>> system. Constructive comments will be appreciated. >>> >>> John, N9JG >> >> John, how high above ground is the antenna? >> >> Frank, VE6CB > > John, just for interest I placed the top of the antenna at 30 ft; which > puts the base at about 8' 3". Using NEC's Sommerfeld/Norton ground with: > sigma = 5 mS/m, and Er = 13. The input impedance computes to 6.57 + > j855.6 ohms. Since this is very close to the edge of the Smith Chart, your > 1 ohm figure is probably within a reasonable margin of error. However I > cannot see how you can match such an impedance with a single element. > > The structure appears to be a very efficient, physically small, antenna. > NEC computes 0.84% copper loss. > > Frank > Article: 221859 of rec.radio.amateur.antenna From: "Frank" References: <4WJLf.1213$dg.9@clgrps13> Subject: Re: 80 m compact loop - progress report Message-ID: <0MLLf.4631$Cp4.2037@edtnps90> Date: Fri, 24 Feb 2006 22:28:12 GMT "John, N9JG" wrote in message news:ogLLf.796419$_o.494459@attbi_s71... >I plan to feed the loop at the side opposite to the side containing the >tuning capacitor. Note that the capacitor is inserted in series with the >loop and is used to tune the loop to resonance at the operating frequency. >A gamma match is used to connect the coax to the loop, and the loop is NOT >cut on the feed side. Ok, thanks. I am sure the loop will work very well. Frank Article: 221860 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: nec simulation - unexpected result ?? References: <1K7Lf.15962$2O6.11668@newssvr12.news.prodigy.com> <43FD4A4F.9010209@comcast.net> <4wkLf.4207$vC4.1279@clgrps12> <43FE9C4F.3050104@comcast.net> <%lKLf.39590$H71.27479@newssvr13.news.prodigy.com> Message-ID: <6TLLf.13321$rL5.8593@newssvr27.news.prodigy.net> Date: Fri, 24 Feb 2006 22:35:46 GMT Owen Duffy wrote: > On that basis, one would have to say that a full wave centre fed > dipole exhibits (at the feed point) resonance similar to a lossy > parallel tuned circuit and should be considered a resonant radiator. I know that is what your gut feeling wishes were true. But a large portion of the RF engineering community considers "anti- resonance" to be the exact opposite of "resonance" and indeed it is the exact opposite on a Smith Chart, being the opposite side of the SWR circle. Semantics strikes again. I'm sure that our Russian counterparts have a completely different word for exactly the same effects. -- 73, Cecil http://www.qsl.net/w5dxp Article: 221861 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: nec simulation - unexpected result ?? References: <15631-43FF0DD8-401@storefull-3255.bay.webtv.net> <11vuv3l7thdn87@corp.supernews.com> Message-ID: Date: Fri, 24 Feb 2006 22:41:54 GMT Roy Lewallen wrote: > Resonance has everything to do with impedance. Resonance is defined as > any frequency at which the impedance is purely resistive; ... In the distant past, when I had a dinosaur for a pet, resonance was defined as the frequency at which the impedance is a purely low impedance. The frequency at which the impedance was a purely high resistance was known at the anti-resonant point, the exact opposite of resonance, and indeed, it was the exact other side of the SWR circle on a Smith Chart. -- 73, Cecil http://www.qsl.net/w5dxp Article: 221862 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Q about balanced feed line References: Message-ID: <4%LLf.13325$rL5.10680@newssvr27.news.prodigy.net> Date: Fri, 24 Feb 2006 22:44:16 GMT Big Endian wrote: > An unbalanced condition would have a meter indication, like current > flow? Balanced the meter needle would not move? Yes, for a balanced condition, the meter needle should not move. -- 73, Cecil http://www.qsl.net/w5dxp Article: 221863 of rec.radio.amateur.antenna From: Dan Jacobson Subject: orchard wire mesh Beverage? Date: Sat, 25 Feb 2006 06:37:57 +0800 Message-ID: <87mzgg4c3e.fsf@jidanni.org> Next door is an hectare large orchard covered with a tree supporting wire mesh, one wire per meter, all two meters above the ground, and grounded to anchors all along its edge. Any Beverage style receiving use? Article: 221864 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Q about balanced feed line Date: Fri, 24 Feb 2006 16:41:31 -0800 Message-ID: <11vv9ts9iv1t23d@corp.supernews.com> References: <11vugpalqdcltd4@corp.supernews.com> Larry Benko wrote: > Hi Roy, > > I have a couple of RF current meters with freq. response from 10KHz to > 100MHZ that are the types used for FCC part 15, DO-160E testing etc. and > have a transfer impedance of 0dB-ohm. They have an opening of about > 1.6" dia. and I sqeeze the feedline together (spacing about 1.5") > temporarily and clamp over both conductors for measurement #1 and clamp > over just 1 of the conductors for measurement #2. I read the output of > the current probe with an RF power meter. In my case the current in a > single conductor was approximately 15dB above the differential current > which seemed to be pretty well balanced. Is there anything wrong with > this approach? > > Larry Benko, W0QE Not that I can see. In my opinion it's the best way to make the measurement. A homebrew version of this is entirely adequate, though, as described in the earlier thread. It's very important to terminate the secondary with a fairly low impedance so the transformer doesn't present a significant impedance to the line. I assume your meter does this internally -- maybe that information is in the transfer impedance you mentioned and which I don't really understand. Roy Lewallen, W7EL Article: 221865 of rec.radio.amateur.antenna From: Dot Subject: Re: nec simulation - unexpected result ?? Message-ID: References: <15631-43FF0DD8-401@storefull-3255.bay.webtv.net> <11vuv3l7thdn87@corp.supernews.com> Date: Fri, 24 Feb 2006 19:29:58 -0500 On Fri, 24 Feb 2006 22:41:54 GMT, Cecil Moore wrote: >Roy Lewallen wrote: >> Resonance has everything to do with impedance. Resonance is defined as >> any frequency at which the impedance is purely resistive; ... > >In the distant past, when I had a dinosaur for a pet, resonance >was defined as the frequency at which the impedance is a purely >low impedance. The frequency at which the impedance was a >purely high resistance was known at the anti-resonant point, >the exact opposite of resonance, and indeed, it was the exact >other side of the SWR circle on a Smith Chart. These days, resonance is described as either: a) the point at which Inductive Reactance and Capacitive Reactance are equal or b) the point at which a load impedence is purely resistive. Looking at your definitions I would suggest that "resonance" is really the point at which the antenna mimics a series resonant circuit, exhibiting a low impedence and "anti-resonance" is the point at which it mimics a parallel resonant circuit, exhibiting a high impedence. It would then be reasonable for a given wire perpendicular to a good ground plane to exhibit "resonance" at odd multiples of a quarter wavelength and "anti-resonance" at even multiples of a quarter wavelength... Translating gives low impedence at odds and high impedence at evens, which is where I started out in this discussion.... Your semantics is correct if you are looking to define an antenna as "a current fed device", but that's not always the case. There are end fed half waves out there... they are voltage fed, they are resonant and they do work. (Ask anyone who owns a "Ringo Ranger".) Article: 221866 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: nec simulation - unexpected result ?? References: <1K7Lf.15962$2O6.11668@newssvr12.news.prodigy.com> <43FD4A4F.9010209@comcast.net> <4wkLf.4207$vC4.1279@clgrps12> <43FE9C4F.3050104@comcast.net> <%lKLf.39590$H71.27479@newssvr13.news.prodigy.com> <6TLLf.13321$rL5.8593@newssvr27.news.prodigy.net> <1140826892.169941.137710@i40g2000cwc.googlegroups.com> Message-ID: Date: Sat, 25 Feb 2006 01:09:44 GMT K7ITM wrote: > I'm not likely to soon adopt "antiresonance" for either condition, as > it sounds way too much like something opposing resonance. In a transmission line with reflections, antiresonance is indeed plus or minus 90 degrees from resonance and "never the twain shall meet". Resonance and antiresonance cannot, by definition, occur at the same point, i.e. if a point is antiresonant, it cannot, by definition, be resonant. Quoting "Transmission Lines and Networks", by Walter C. Johnson, PhD. (one of the heavyweight gurus of the mid-20th- century) page 156: "When the lossless line is an odd number of quarter wavelengths long, the sending-end impedance is theoretically infinite (inversion of the receiving-end impedance). The actual impedance, considering losses, is a very large resistance, and the line is said to be ANTIRESONANT." (Capitals substituted for italics for obvious reasons) So your argument is with Walter C. Johnson, PhD, ex-chairman of the Department of Electrical Engineering at Princeton University, not with me. -- 73, Cecil http://www.qsl.net/w5dxp Article: 221867 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: nec simulation - unexpected result ?? References: <15631-43FF0DD8-401@storefull-3255.bay.webtv.net> <11vuv3l7thdn87@corp.supernews.com> Message-ID: Date: Sat, 25 Feb 2006 01:13:53 GMT Dot wrote: > Looking at your definitions I would suggest that "resonance" is really the > point at which the antenna mimics a series resonant circuit, exhibiting a > low impedence and "anti-resonance" is the point at which it mimics a > parallel resonant circuit, exhibiting a high impedence. True, but I cannot take credit for the definition which comes from "Transmission Lines and Networks", by Walter C. Johnson, PhD, guru and chairman of the Department of Electrical Engineering, Princeton University during the 1940's and 1950's. -- 73, Cecil http://www.qsl.net/w5dxp Article: 221868 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: nec simulation - unexpected result ?? References: <1K7Lf.15962$2O6.11668@newssvr12.news.prodigy.com> <43FD4A4F.9010209@comcast.net> <4wkLf.4207$vC4.1279@clgrps12> <43FE9C4F.3050104@comcast.net> <%lKLf.39590$H71.27479@newssvr13.news.prodigy.com> <6TLLf.13321$rL5.8593@newssvr27.news.prodigy.net> <1140826892.169941.137710@i40g2000cwc.googlegroups.com> Message-ID: Date: Sat, 25 Feb 2006 01:30:22 GMT Cecil Moore wrote: > In a transmission line with reflections, antiresonance is > indeed plus or minus 90 degrees from resonance and "never > the twain shall meet". Resonance and antiresonance cannot, > by definition, occur at the same point, i.e. if a point > is antiresonant, it cannot, by definition, be resonant. One more thought: In a transmission line with reflections, a voltage node is located at a point of resonance. A voltage anti-node is located at a point of anti-resonance. Makes perfect sense to me. -- 73, Cecil http://www.qsl.net/w5dxp Article: 221869 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: nec simulation - unexpected result ?? References: <15631-43FF0DD8-401@storefull-3255.bay.webtv.net> <0MCdnSUB24eaMmLeRVn-tA@comcast.com> Message-ID: Date: Sat, 25 Feb 2006 01:35:20 GMT Amos Keag wrote: > If the feed is 'changing the resonance' then there is a problem with the > feed!! Not at all. As you can see at: http://www.qsl.net/w5dxp/notuner.htm, I use "the feed" for the specific purpose of changing the resonant frequency of the antenna system. The impedance transforming series- section is really a series stub which resonants the entire antenna system. -- 73, Cecil http://www.qsl.net/w5dxp Article: 221870 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Q about balanced feed line References: <0epuv1lpbqi5adut9qo1ijkp5k38hro11k@4ax.com> <22uuv1lofv5vcri03nnk30ppc4s779bbth@4ax.com> Message-ID: Date: Sat, 25 Feb 2006 01:39:50 GMT Amos Keag wrote: > I've used a transmatch for almost 45 years out of 50+ years in Ham > Radio. If my antenna has a problem the settings for a 'match' [in > quotes] change!! How do you know when the settings for an SGC-230 autotuner change? -- 73, Cecil http://www.qsl.net/w5dxp Article: 221871 of rec.radio.amateur.antenna From: Dot Subject: Re: nec simulation - unexpected result ?? Message-ID: References: <15631-43FF0DD8-401@storefull-3255.bay.webtv.net> <11vuv3l7thdn87@corp.supernews.com> Date: Fri, 24 Feb 2006 21:21:23 -0500 On Sat, 25 Feb 2006 01:13:53 GMT, Cecil Moore wrote: >Dot wrote: >> Looking at your definitions I would suggest that "resonance" is really the >> point at which the antenna mimics a series resonant circuit, exhibiting a >> low impedence and "anti-resonance" is the point at which it mimics a >> parallel resonant circuit, exhibiting a high impedence. > >True, but I cannot take credit for the definition which comes from >"Transmission Lines and Networks", by Walter C. Johnson, PhD, guru >and chairman of the Department of Electrical Engineering, Princeton >University during the 1940's and 1950's. Oh him [grin]... he was one of my better students... Just kidding... I wasn't even born yet. Article: 221872 of rec.radio.amateur.antenna From: Dot Subject: Re: Q about balanced feed line Message-ID: References: <0epuv1lpbqi5adut9qo1ijkp5k38hro11k@4ax.com> <22uuv1lofv5vcri03nnk30ppc4s779bbth@4ax.com> Date: Fri, 24 Feb 2006 21:24:21 -0500 On Fri, 24 Feb 2006 20:21:28 -0500, Amos Keag wrote: >I've used a transmatch for almost 45 years out of 50+ years in Ham >Radio. If my antenna has a problem the settings for a 'match' [in >quotes] change!! That indicates something has happened. > >The system SWR increase can be seen in the changes transmatch settings. I bow to your experience, my new friend. You've been doing this almost as long as I've been alive. I'd bet real money you've learned a thing or three along the way too! Article: 221873 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: nec simulation - unexpected result ?? Date: Fri, 24 Feb 2006 19:49:19 -0800 Message-ID: <11vvku12b8t8398@corp.supernews.com> References: <15631-43FF0DD8-401@storefull-3255.bay.webtv.net> <11vuv3l7thdn87@corp.supernews.com> Dot wrote: > On Fri, 24 Feb 2006 22:41:54 GMT, Cecil Moore wrote: > >> Roy Lewallen wrote: >>> Resonance has everything to do with impedance. Resonance is defined as >>> any frequency at which the impedance is purely resistive; ... >> In the distant past, when I had a dinosaur for a pet, resonance >> was defined as the frequency at which the impedance is a purely >> low impedance. The frequency at which the impedance was a >> purely high resistance was known at the anti-resonant point, >> the exact opposite of resonance, and indeed, it was the exact >> other side of the SWR circle on a Smith Chart. > > These days, resonance is described as either: > > a) the point at which Inductive Reactance and Capacitive Reactance are equal > or > b) the point at which a load impedence is purely resistive. The two points are exactly the same. > Looking at your definitions I would suggest that "resonance" is really the > point at which the antenna mimics a series resonant circuit, exhibiting a > low impedence and "anti-resonance" is the point at which it mimics a > parallel resonant circuit, exhibiting a high impedence. The high-impedance full-wave resonant point (for a dipole; half-wave resonant point for a monopole) is sometimes called "anti-resonance", but not commonly, and mostly in older literature. It's a true point of resonance, that is, where the reactance is zero. I don't believe I've ever heard the term "anti-resonance" applied to other high-impedance resonant circuits, such as a tank circuit. > It would then be reasonable for a given wire perpendicular to a good ground > plane to exhibit "resonance" at odd multiples of a quarter wavelength and > "anti-resonance" at even multiples of a quarter wavelength... Translating > gives low impedence at odds and high impedence at evens, which is where I > started out in this discussion.... If you choose to call the high-impedance resonant points "anti-resonance", that's true. But again, they're points where the reactance is zero, just like the points you're calling "resonant". The only difference is that the impedance is high and the antenna acts more like a parallel tuned circuit at nearby frequencies rather than a series tuned circuit. > Your semantics is correct if you are looking to define an antenna as "a > current fed device", but that's not always the case. There are end fed half > waves out there... they are voltage fed, they are resonant and they do work. > (Ask anyone who owns a "Ringo Ranger".) No, the definition of resonance has nothing to do with how an antenna is fed. The impedance of the antenna doesn't change with the feed method (assuming of course that it has a single feed point), and therefore its resonant frequencies don't change with the feed method. (You can, of course, alter the resonant frequencies of an antenna *system* by adding reactance at the feedpoint or elsewhere.) And an antenna doesn't have to be resonant (that is, have a non-reactive feedpoint impedance) to "work". Resonance is only an indication of the reactance of the input impedance, and has nothing to do with an antenna's gain, pattern, bandwidth, or other performance characteristics. Roy Lewallen, W7EL Article: 221874 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Q about balanced feed line Date: Fri, 24 Feb 2006 19:52:04 -0800 Message-ID: <11vvl35rqugfjb6@corp.supernews.com> References: <11vugpalqdcltd4@corp.supernews.com> <11vv9ts9iv1t23d@corp.supernews.com> Larry Benko wrote: > Roy, > > It is amazing how a simple concept such as impedance can be made obscure > but most current probes are spec'd this way by the manufacturers and > test procedures for DO-160E (FAA aircraft testing) call out probes the > same way. By saying that a current probe has a transfer impedance of > 0dB-ohm means 0dB relative to 1 ohm, but R = V/I so 0dB-ohm means that > for 1A of current thru the primary of the probe produces 1V across a 50 > ohm load. Similarly a -20db-ohm transfer means that 1A produces .1V > across a 50 ohm load. For most of us, this means a 1 turn primary and a > 50 turn secondary which yields a theoretical primary impedance or 0.02 > ohms. One of the probes I have says the primary impedance is less than > .1 ohm. > > Larry Benko, W0QE Thanks for the explanation. My concern is with the insertion impedance, which at 0.02 or even 0.1 ohm, is certainly adequately low for this device -- as long as it's properly terminated. Roy Lewallen, W7EL