20100510.ba v04_n332.bam.20100510 >From ???@??? Mon May 10 17:27:26 2010 -0500 Date: Mon, 10 May 2010 23:27:04 GMT From: Old Tube Radios To: Old Tube Radios Subject: BOATANCHORS digest 4332 Message-Id: <20100510232705.67266910CCE@minime.theporch.com> BOATANCHORS Digest 4332 Topics covered in this issue include: 1) Re: Roof mounted tower by Garey Barrell 2) Restoration Book on the R1155 Receiver by Jerry Proc 3) Re: Restoration Book on the R1155 Receiver by spr@earthlink.net 4) Re: Restoration Book on the R1155 Receiver by WA5CAB@cs.com 5) Identify Drone Receiver by "Lenox Carruth" 6) Re: Identify Drone Receiver by aafradio 7) Re: Restoration Book on the R1155 Receiver by Jerry Proc 8) Help with linear amp. by ray jefferson 9) RE: Help with linear amp. by "Jim Garland" <4cx250b@muohio.edu> 10) David Medley KI6QE SK by Dan Arney 11) KSM Schedule Saturday 8 May by Richard Dillman 12) BA people- near Warren OH. by wb3fau@att.net 13) Manual for Heathkit linear SB221Amplifier by ray jefferson 14) EVENT REPORT: International Marconi Day 2010 by Richard Dillman 15) See you at Dayton by Nick England 16) Re: Manual for Heathkit linear SB221Amplifier by Al Parker 17) GPR90 by "Guido" 18) Re: GPR90 by "Arden Allen" 19) RE: GPR90 by "Singley, Rodger" 20) Re: GPR90----> Fuse technology by john 21) Re: GPR90 by "Arden Allen" 22) RE: GPR90 by "Jim Garland" <4cx250b@muohio.edu> ---------------------------------------------------------------------- Message-ID: <4BE3825E.4000600@mindspring.com> Date: Thu, 06 May 2010 23:00:46 -0400 From: Garey Barrell MIME-Version: 1.0 To: Old Tube Radios Subject: Re: Roof mounted tower Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit David Thompson wrote: > > You can also use rohn type 25G bracketed to the house or garage. You > cannot safely have more than 2 10 foot sections above the bracket > before you must guy it even using small antennas. I don't know what > kind of soil you have there but Dave Johnson, K4SSU installed over 50 > Rohn 25 and 45 towers next to house or garage in the Atlanta metro are > and he never put down an extensive concrete base. But he guyed all of > the towers. > > Hi Dave - SSU installed mine in Atlanta. 25G bracketed at 16' to the house. Total of four 10'sections plus top section with three el tribander (CC ATB-34) and seven el 2M Yagi 8' above that. No guys, flat base sitting on concrete patio with single large bolt down the middle. 29 years including two near miss tornados! 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line& TR-4/C Service Supplement CDs ------------------------------ Message-ID: <995556.50524.qm@web112309.mail.gq1.yahoo.com> Date: Thu, 6 May 2010 20:02:34 -0700 (PDT) From: Jerry Proc Subject: Restoration Book on the R1155 Receiver To: Old Tube Radios MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable As noted in the May/June 2010 issue of The Canadian Amateur Magazine: http://r1155.blogspot.com/ The document indicates a cost of =A320.00 which ought to convert to somewhe= re around $US62-63. This includes airmail post and packing from Australia. I personally have not seen the book. My only role here is that of a messeng= er to make its availibity known.=20 -- Regards, Jerry Proc E-mail: jerry7proc@yahoo.com=0A=0A ------------------------------ Message-ID: <27610257.1273202995869.JavaMail.root@elwamui-karabash.atl.sa.earthlink.net> Date: Thu, 6 May 2010 23:29:55 -0400 (EDT) From: spr@earthlink.net To: Old Tube Radios Subject: Re: Restoration Book on the R1155 Receiver Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Folks, I think Jerry's currency conversion is off about a factor of 2. GBP20 is ab= out US $ 30-40. /scott -----Original Message----- >From: Jerry Proc >Sent: May 6, 2010 11:02 PM >To: Old Tube Radios >Subject: Restoration Book on the R1155 Receiver > >As noted in the May/June 2010 issue of The Canadian Amateur Magazine: >http://r1155.blogspot.com/ > >The document indicates a cost of =C2=A320.00 which ought to convert to som= ewhere around $US62-63. This includes airmail post and packing from Austral= ia. > >I personally have not seen the book. My only role here is that of a messen= ger to make its availibity known.=20 >-- >Regards, >Jerry Proc >E-mail: jerry7proc@yahoo.com > > > ------------------------------ From: WA5CAB@cs.com Message-ID: <2e5bf.9541f4a.3914eb99@cs.com> Date: Fri, 7 May 2010 00:05:45 EDT Subject: Re: Restoration Book on the R1155 Receiver To: Old Tube Radios MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_2e5bf.9541f4a.3914eb99_boundary" --part1_2e5bf.9541f4a.3914eb99_boundary Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable Scott, I was thinking the same thing. I bought an ASDL Router last week out of= =20 the UK and the exchange rate was 1 USD =3D 0.637035 GBP. Or turned over,= =20 $1.5698 =3D L1.00. So L20.00 =3D $31.40. However, we might see $4.00 to the pound again soon. They've already=20 started jacking with Tricare, which they promised not to do.=20 In a message dated 5/6/2010 10:30:17 PM Central Daylight Time,=20 spr@earthlink.net writes:=20 > Folks, >=20 > I think Jerry's currency conversion is off about a factor of 2. GBP20 is= =20 > about US $ 30-40. >=20 > /scott >=20 >=20 > -----Original Message----- > >From: Jerry Proc > >Sent: May 6, 2010 11:02 PM > >To: Old Tube Radios > >Subject: Restoration Book on the R1155 Receiver > > > >As noted in the May/June 2010 issue of The Canadian Amateur Magazine: > >http://r1155.blogspot.com/ > > > >The document indicates a cost of =A320.00 which ought to convert to=20 > somewhere around $US62-63. This includes airmail post and packing from= Australia. > > > >I personally have not seen the book. My only role here is that of a=20 > messenger to make its availibity known.=20 > >-- > >Regards, > >Jerry Proc > >E-mail: jerry7proc@yahoo.com >=20 Robert & Susan Downs - Houston wa5cab dot com (Web Store) MVPA 9480 --part1_2e5bf.9541f4a.3914eb99_boundary Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ---REMAINDER OF MESSAGE TRUNCATED--- * * This post contains a forbidden message format * * (such as an attached file, a v-card, HTML formatting) * * Mail Lists at theporch.com only accept PLAIN TEXT * * If your postings display this message your mail program * * is not set to send PLAIN TEXT ONLY and needs adjusting * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * --part1_2e5bf.9541f4a.3914eb99_boundary-- ------------------------------ From: "Lenox Carruth" To: Old Tube Radios Subject: Identify Drone Receiver Date: Fri, 7 May 2010 08:40:42 -0500 Message-ID: <00b301caedea$e37c3a20$aa74ae60$@net> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en-us The following was received from Tom Aschenbrenner who is a list member = but is in Wisconsin and can't access the list there: I just found a real interesting thing. I went to a small town 5 miles from Manitowoc called Two Rivers...there are a bunch of fishing = companies there and one of them has misc stuff that over the years has = been drug up by the fishing nets out on the lake...well one of the = things is a WWII target drone! It has a small 4 cylinder engine, it's = made of Alum has still has the radio control equipment in it! Since I = can't post to boat anchors from here could you put a request out to see = what a receiver R196C/APW-26Y is? Apparently during the war they would = fly these things by remote control out over the lake and gunners would = be trained on them. This one doesn't seem to have any bullet holes! Tom A. Anybody got any info on the R196C/APW-26Y? Thanks! Lenox ------------------------------ Message-ID: <4BE41B17.7090507@aafradio.org> Date: Fri, 07 May 2010 09:52:23 -0400 From: aafradio MIME-Version: 1.0 To: Old Tube Radios CC: Old Tube Radios Subject: Re: Identify Drone Receiver Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Interestingly enough, http://www.designation-systems.net/dusrm/app4/martin-845a.html has a much later application! 73, Mike On 5/7/2010 9:40 AM, Lenox Carruth wrote: > The following was received from Tom Aschenbrenner who is a list member but is in Wisconsin and can't access the list there: > > I just found a real interesting thing. I went to a small town > 5 miles from Manitowoc called Two Rivers...there are a bunch of fishing companies there and one of them has misc stuff that over the years has been drug up by the fishing nets out on the lake...well one of the things is a WWII target drone! It has a small 4 cylinder engine, it's made of Alum has still has the radio control equipment in it! Since I can't post to boat anchors from here could you put a request out to see what a receiver R196C/APW-26Y is? Apparently during the war they would fly these things by remote control out over the lake and gunners would be trained on them. This one doesn't seem to have any bullet holes! > ------------------------------ Message-ID: <633739.19739.qm@web112310.mail.gq1.yahoo.com> Date: Fri, 7 May 2010 09:55:11 -0700 (PDT) From: Jerry Proc Subject: Re: Restoration Book on the R1155 Receiver To: Old Tube Radios MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable The TCA Article mentions a cost of $Cdn 63.30 and since the Cdn and US curr= encies are nearly on par I just passed it on that way. =20 -- -- Regards, Jerry Proc E-mail: jerry7proc@yahoo.com --- On Thu, 5/6/10, spr@earthlink.net wrote: > From: spr@earthlink.net > Subject: Re: Restoration Book on the R1155 Receiver > To: "Old Tube Radios" > Received: Thursday, May 6, 2010, 11:29 PM > Folks, >=20 > I think Jerry's currency conversion is off about a factor > of 2. GBP20 is about US $ 30-40. >=20 > /scott >=20 >=20 > -----Original Message----- > >From: Jerry Proc > >Sent: May 6, 2010 11:02 PM > >To: Old Tube Radios > >Subject: Restoration Book on the R1155 Receiver > > > >As noted in the May/June 2010 issue of The Canadian > Amateur Magazine: > >http://r1155.blogspot.com/ > > > >The document indicates a cost of =A320.00 which ought to > convert to somewhere around $US62-63. This includes airmail > post and packing from Australia. > > > >I personally have not seen the book. My only role here > is that of a messenger to make its availibity known.=20 > >-- > >Regards, > >Jerry Proc > >E-mail: jerry7proc@yahoo.com > > > > > > >=20 > =0A=0A ------------------------------ MIME-Version: 1.0 Date: Fri, 7 May 2010 16:14:54 -0600 Message-ID: Subject: Help with linear amp. From: ray jefferson To: Old Tube Radios Content-Type: text/plain; charset=ISO-8859-1 Greetings: need confirmation! My setup with my old Heathkit 212 is as follows ....Exciter output 100 watts (which is ok by Heathkit manual) followed closely with manual instructions with the amplifier( Old Heathkit 212)...using two 3=500Z tubes parallel in grounded grid circuit. Input shows tuned and loaded to (600) watts ( would take more loading but I hold it to this)linear out......then to MFJ SWR/Wattmeter...out to antenna which is threeelement beam and shows a low low SWR etc.Incidentally....MFJ meter works perfectly when working alone with the Exciter alone. I load the linear according to instructions in manual to 600 watts input....all o.k.. When I check the linear outputit reads 300watts to the antenna.Is this correct or should it be showing more into the antenna??? Is the grounded grid working to only 50percent or have I another problem ? Thanks for your comments! Ray Jefferson, W7FNI.....since 1934 Remember. were all in this together ------------------------------ From: "Jim Garland" <4cx250b@muohio.edu> To: Old Tube Radios Subject: RE: Help with linear amp. Date: Fri, 7 May 2010 16:59:49 -0600 Message-ID: <000b01caee39$00bccc00$bd00a8c0@Garland> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Ray, The 300Watts is about right as far as efficiency is concerned, but you'll quickly damage your 3-500Zs by tuning your amplifier that way. If you're loading the amp only to 600W input, with 100 Watts of drive, then the amplifier is grossly underloaded and your grid current is WAY too high. Also, the amplifier is undoubtedly flat-topping severely, and producing distortion and splatter. You didn't mention what kind of amplifier you're using, but I"d recommend loading it for maximum output with 100W drive. If it's, e.g., an SB-220, then then you should be getting in the neighborhood of 1000-1100W OUTPUT. The grid current under these conditions should be in the range of 200-230mA, or thereabouts, and the amplifier will be properly tuned. Then, once it's tuned, you can back off your drive power to get whatever power output you desire. 73, Jim W8ZR > -----Original Message----- > From: owner-boatanchors@theporch.com [mailto:owner-boatanchors@theporch.com] On > Behalf Of ray jefferson > Sent: Friday, May 07, 2010 4:15 PM > To: Old Tube Radios > Subject: Help with linear amp. > > Greetings: need confirmation! My setup with my old Heathkit 212 is > as follows ....Exciter output 100 watts (which is ok by Heathkit > manual) followed closely with manual instructions with the amplifier( > Old Heathkit 212)...using two 3=500Z tubes parallel in grounded grid > circuit. Input shows tuned and loaded to (600) watts ( would take > more loading but I hold it to this)linear out......then to MFJ > SWR/Wattmeter...out to antenna which is threeelement beam and shows a > low low SWR etc.Incidentally....MFJ meter works perfectly when working > alone with the Exciter alone. I load the linear according to > instructions in manual to 600 watts input....all o.k.. When I check > the linear outputit reads 300watts to the antenna.Is this correct or > should it be showing more into the antenna??? Is the grounded grid > working to only 50percent or have I another problem ? Thanks for > your comments! > > Ray Jefferson, > W7FNI.....since 1934 > Remember. were all in this together ------------------------------ Message-ID: <4BE4B307.5060802@pacbell.net> Date: Fri, 07 May 2010 19:40:39 -0500 From: Dan Arney MIME-Version: 1.0 To: Old Tube Radios Subject: David Medley KI6QE SK Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit David became a SK MAY 2 2010. IN TUCSON RIP FRIEND, HANK KN6DI ------------------------------ Message-ID: <100972.1273332532842.JavaMail.root@elwamui-norfolk.atl.sa.earthlink.net> Date: Sat, 8 May 2010 08:28:52 -0700 (GMT-07:00) From: Richard Dillman To: Old Tube Radios Subject: KSM Schedule Saturday 8 May Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit In an earlier message we announced that the KSM early press and weather broadcast would be unavailable. Due to a change of personnel schedules the KSM early CW press and weather broadcast will be available as usual today beginning at 1000pdt/1700gmt. RTTY service will be unavailable as previously announced. K6KPH will be available earlier than usual beginning at 1000pdt/1700gmt. Please see http://www.radiomarine.org for frequency information for both stations. Regards, RD ================================= Richard Dillman Chief Operator, Coast Station KSM Maritime Radio Historical Society http://www.radiomarine.org ================================= ------------------------------ From: wb3fau@att.net To: Old Tube Radios Subject: BA people- near Warren OH. Date: Sat, 08 May 2010 20:40:47 +0000 Message-Id: <050820102040.23348.4BE5CC4A0005A01A00005B3422243322829B0A02D29B9B0EBF9A0E00CC0D99@att.net> Just a note to BA people living near I90 @ SR45. [NE OHIO] I travel most weekends in this area. I have breakfast at the Flying J truck stop and continue on to Mentor, OH. I do this either Friday evening, Saturday or Sunday mornings. I buy, sell and trade BAs. I have a few items for sale or trade I can bring to the Flying J. These are receivers, transmitters and audio gear. I continue on to Mentor OH. to visit my Mom, who is in a retirees home. Contact me by direct email if you would like to join me for breakfast and some horse- trading! wb3fau@att.net Russ Erie PA. ------------------------------ MIME-Version: 1.0 Date: Sun, 9 May 2010 11:52:08 -0600 Message-ID: Subject: Manual for Heathkit linear SB221Amplifier From: ray jefferson To: Old Tube Radios Content-Type: text/plain; charset=ISO-8859-1 greetings: I am in dire need of a manual for th Heathkit modelSB221 or lacking that I could use a copy of schematic for same. Any suggestions will be appreciated.. ------------------------------ Message-ID: <13967687.1273433391193.JavaMail.root@elwamui-milano.atl.sa.earthlink.net> Date: Sun, 9 May 2010 15:29:51 -0400 (EDT) From: Richard Dillman To: Old Tube Radios Subject: EVENT REPORT: International Marconi Day 2010 Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit The MRHS two day event for International Marconi Day 2010 was a great success. Demonstrations and presentations were held at the Marconi Conference Center in Marshall, CA, site of the original Marconi 1913 trans-Pacific receive site. The KPH transmitters at the 1913 Marconi receive site in Bolinas, CA, were keyed remotely. We suspect we may have been the only stations (KPH and K6KPH) operating from both the transmit and receive sites of a Marconi station but would love to hear from others who accomplished this feat.. KPH was on MF and 4Mc. Two ships, SS JEREMIAH O'BRIEN/KXCH and SS RED OAK VICTORY/KYVM were worked on MF. The KPH wheel was sent on 4mc. K6KPH was on 3.5Mc and 7Mc. In addition to the operating demonstrations numerous presentations were made each day and a walking tour of the site was conducted. In addition, the ominous message EAT A RAT was transmitted. For full details and plenty of photos please see the MRHS Web site at: http://radiomarine.org/ VY 73, RD ================================= Richard Dillman Chief Operator, Coast Station KSM Maritime Radio Historical Society http://www.radiomarine.org ================================= ------------------------------ MIME-Version: 1.0 Date: Sun, 9 May 2010 16:18:28 -0400 Message-ID: Subject: See you at Dayton From: Nick England To: Old Tube Radios Content-Type: text/plain; charset=ISO-8859-1 Howdy gang - John K4OZY and I will be at the usual spaces 2508-2509, with interesting stuff for sale or trade. I hope to give away 20 boxes of 73, CQ, Ham Radio, & QST; and I hope to not give away a full-up Drake C-Line and a Squires-Sanders SS-1R with speaker, noise blanker, and panadaptor (No, I won't ship it - pickup at Dayton only). And there will be boxes of other interesting stuff too. We'll be there Thursday and Friday, probably not Saturday. Looking for - RACAL RA6790/GM (R-2174/URR), receiver, Navy TTY multiplex gear (AN/FCC-3, AN/FGC-5) & other 1950's-60's Navy communications gear cheers, Nick K4NYW www.navy-radio.com ------------------------------ Message-ID: <4BE72510.5000006@ec.rr.com> Date: Sun, 09 May 2010 17:11:44 -0400 From: Al Parker MIME-Version: 1.0 To: Old Tube Radios CC: Old Tube Radios Subject: Re: Manual for Heathkit linear SB221Amplifier Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit try someone else on a list today said their Heathkit manuals were well done. Al, W8UT www.boatanchors.org www.hammarlund.info "There is nothing -- absolutely nothing -- half so much worth doing as simply messing about in boats" Ratty, to Mole On 5/9/2010 1:52 PM, ray jefferson wrote: > greetings: I am in dire need of a manual for th Heathkit modelSB221 > or lacking that I could use a copy of schematic for same. Any > suggestions will be appreciated.. > > ------------------------------ Message-Id: <81r3gj$1k2367p@avas3.coqui.net> From: "Guido" To: Old Tube Radios Subject: GPR90 Date: Sun, 9 May 2010 20:51:55 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hello gents, Sometime ago I reported about my newly acquired TMC GPR90 and its restoration to a fully functional unit. I was checking the manual and the 2 amp fuse AC line fuse is not detailed as being a fast or slow blow type. If anyone knows this detail I will appreciate it. 73s Guido KP4FAR ------------------------------ Message-ID: <001601caf076$4a5e1f50$cd9d480c@KB6NAX> From: "Arden Allen" To: Old Tube Radios Subject: Re: GPR90 Date: Mon, 10 May 2010 12:23:32 -0700 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit > ......I was checking the manual and the 2 amp fuse AC line fuse is not detailed as being a fast or slow blow type. If anyone knows this detail I will appreciate it. I have learned not to put a lot of faith in the type and value of fuses manufacturers specify for their equipment. A slow blow fuse should only be used when the cold start surge is appreciably higher than the warmed up operating current. Transmitters with high peak operating currents should only use fast blow fuses properly sized to sustain the peak currents. A slow blow fuse where not needed may not blow quickly enough to prevent damage to critical components. Your GPR90 will probably be better protected with a fast blow fuse. Arden Allen KB6NAX Adopt a shelter dog, save an innocent life, and make a friend forever =:-) ------------------------------ Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Subject: RE: GPR90 Date: Mon, 10 May 2010 15:03:15 -0500 Message-ID: From: "Singley, Rodger" To: Old Tube Radios I agree with Arden on this and my GPR-90 has a regular fuse installed. = In vintage gear that start with high inrush currents, in many cases you = can add a properly sized inrush limiter and use it with a standard fuse = instead of relying upon a time delay fuse.=20 Jim W8ZR published an excellent article about inrush limiters and the = proper sizing of fuses with his Viking 500 restoration in Electric Radio = July '97. Rodger WQ9E -----Original Message----- From: owner-boatanchors@theporch.com on behalf of Arden Allen Sent: Mon 5/10/2010 2:23 PM To: Old Tube Radios Subject: Re: GPR90 =20 > ......I was checking the manual and the 2 amp fuse AC line fuse is not detailed as being a fast or slow blow type. = If anyone knows this detail I will appreciate it. I have learned not to put a lot of faith in the type and value of fuses manufacturers specify for their equipment. A slow blow fuse should only = be used when the cold start surge is appreciably higher than the warmed up operating current. Transmitters with high peak operating currents = should only use fast blow fuses properly sized to sustain the peak currents. A slow blow fuse where not needed may not blow quickly enough to prevent damage to critical components. Your GPR90 will probably be better = protected with a fast blow fuse. Arden Allen KB6NAX Adopt a shelter dog, save an innocent life, and make a friend forever =3D:-) ------------------------------ Message-Id: <6.2.1.2.2.20100510185017.031d5da0@pop-server.nc.rr.com> Date: Mon, 10 May 2010 18:59:33 -0400 To: Old Tube Radios From: john Subject: Re: GPR90----> Fuse technology Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed It's interesting to read the fine print in a fuse specification (OK, I'm easily amused!) A typical "fast acting" 3AG item : Rated current Opening time 100% 4 hours, Minimum 135% . 1 hour, Maximum 200% 5 sec., Maximum They're also very loosely spec'd when it comes to other operating conditions... frequently a "typical" curve, or "average" graphs without precise data. It's a difficult condition to manage...a thin piece of meltable metal and a widely ranging expectation of protection. John k5MO At 03:23 PM 5/10/2010, Arden Allen wrote: > > ......I was checking the manual and the 2 >amp fuse AC line fuse is not detailed as being a fast or slow blow type. If >anyone knows this detail I will appreciate it. > >I have learned not to put a lot of faith in the type and value of fuses >manufacturers specify for their equipment. A slow blow fuse should only be >used when the cold start surge is appreciably higher than the warmed up >operating current. Transmitters with high peak operating currents should >only use fast blow fuses properly sized to sustain the peak currents. A >slow blow fuse where not needed may not blow quickly enough to prevent >damage to critical components. Your GPR90 will probably be better protected >with a fast blow fuse. > >Arden Allen >KB6NAX > >Adopt a shelter dog, >save an innocent life, >and make a friend forever =:-) ------------------------------ Message-ID: <003001caf094$633cb770$259f480c@KB6NAX> From: "Arden Allen" To: Old Tube Radios Subject: Re: GPR90 Date: Mon, 10 May 2010 15:46:52 -0700 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit > ......in many cases you can add a properly sized inrush limiter and use it with a standard fuse instead of relying upon a time delay fuse. About the only thing an inrush limiter will protect is the fuse in a boatanchor. But with an inrush limiter you can reduce the amperage of the fuse for better protection from fault currents like 'lytic shorts. Arden Allen KB6NAX Adopt a shelter dog, save an innocent life, and make a friend forever =:-) ------------------------------ From: "Jim Garland" <4cx250b@muohio.edu> To: Old Tube Radios Subject: RE: GPR90 Date: Mon, 10 May 2010 17:26:51 -0600 Message-ID: <002501caf098$46c60c00$bd00a8c0@Garland> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit > About the only thing an inrush limiter will protect is the fuse in a > boatanchor. But with an inrush limiter you can reduce the amperage of the > fuse for better protection from fault currents like 'lytic shorts. > > Arden Allen > KB6NAX Inrush limiters also take some of the burden off a power switch, especially if a rectifier tube has been swapped for Si diodes. And even if not, I've often measured more than a 50% reduction in the startup current surge. I agree, however, that they're no substitute for a fuse! 73, Jim W8ZR ------------------------------ End of BOATANCHORS Digest 4332 ******************************