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161. Re: [Amps] 70cm amp (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Sat, 11 Jun 2011 01:17:29 +0000 (UTC)
Thanks Mel.   It's certainly not on par with what the highly expierenced builders in this group do, but I guess we all start somewhere.  I've learned quite a bit during the process and already have a
/archives//html/Amps/2011-06/msg00146.html (9,010 bytes)

162. [Amps] Top vs bottom posting (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Thu, 16 Jun 2011 19:35:29 +0000 (UTC)
Classic queue vs. stack. _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
/archives//html/Amps/2011-06/msg00183.html (6,603 bytes)

163. [Amps] old commercial amp (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Thu, 16 Jun 2011 23:57:37 +0000 (UTC)
Now here's an amp! http://cgi.ebay.com/Johnson-Kilowatt-Desk-Transmitter-/330577398599?pt=LH_DefaultDomain_0&hash=item4cf7f2cb47 _______________________________________________ Amps mailing list Amps
/archives//html/Amps/2011-06/msg00195.html (7,140 bytes)

164. Re: [Amps] old commercial amp (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Fri, 17 Jun 2011 02:32:27 +0000 (UTC)
The AN/FRT-31 is likely the ultimate ba, but not for typical house hold use. _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/
/archives//html/Amps/2011-06/msg00200.html (7,487 bytes)

165. [Amps] 8874/3cx400a7 (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Fri, 17 Jun 2011 12:20:41 +0000 (UTC)
A question I'm sure the experienced amp builders can answer.  I was reading through the Eimac 8874 datasheet last night and found this paragraph: quote: HEATER/CATHODE OPERATION - The rated heater vo
/archives//html/Amps/2011-06/msg00206.html (7,969 bytes)

166. Re: [Amps] 8874/3cx400a7 (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Fri, 17 Jun 2011 13:00:48 +0000 (UTC)
Interestingly enough, the 3cx800A7 and 3cpx800A7 sheets don't have that paragraph.  I suspect because they are only spec'ed to 350 Mhz. On the other hand, the 3cx800U7 has a similar paragraph showing
/archives//html/Amps/2011-06/msg00209.html (9,288 bytes)

167. [Amps] Risks from continuous discharge of high voltage ?? (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Sun, 3 Jul 2011 23:40:32 +0000 (UTC)
I seem to remember reading or hearing somewhere that someone used a 3-500 or 4-1000 to produce x-rays running the tube basically at it's failure point. _______________________________________________
/archives//html/Amps/2011-07/msg00023.html (8,266 bytes)

168. Re: [Amps] High SWR (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Tue, 5 Jul 2011 19:23:16 +0000 (UTC)
Since you believe resonance was well understood before the invention of of the vacuum tube,  can you tell me what it was understood to be? As an amateur luthier... O f course  it was, any musical in
/archives//html/Amps/2011-07/msg00055.html (7,628 bytes)

169. Re: [Amps] New NXP BLF578XR 1200W LDMOS FET is "indestructible" (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Fri, 22 Jul 2011 20:16:12 +0000 (UTC)
  Over the years I've heard many people say that adequately cooling a transistor is difficult because it is so small.  It's really difficult for me to wrap my brain around that statement though after
/archives//html/Amps/2011-07/msg00265.html (9,774 bytes)

170. Re: [Amps] New NXP BLF578XR 1200W LDMOS FET is "indestructible" (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Fri, 22 Jul 2011 22:07:33 +0000 (UTC)
Well that is exactly my point.  I think with power mosfets, the drain is usually part of the outside package.  The physical parts of the tube is small, the cooler is just an external part.  case and
/archives//html/Amps/2011-07/msg00268.html (11,368 bytes)

171. Re: [Amps] MRF141g amp kit offered by CCI (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Tue, 23 Aug 2011 16:10:19 +0000 (UTC)
Hi Ian, I've had similar expierences with Han, although I was trying to get the kit to work from 1.8 to 60 Mhz.  I found it very difficult to bias the kit and to keep oscillation from occuring and ve
/archives//html/Amps/2011-08/msg00155.html (8,550 bytes)

172. [Amps] Stripline design (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Thu, 5 Jan 2012 01:20:58 +0000 (UTC)
Hi group, I have a homebrew 70 cm stripline amplifier built around the 3cx400A7 tube. As everyone know's, it's getting rare and expensive. I was thinking that it would be really easy to change over t
/archives//html/Amps/2012-01/msg00043.html (8,962 bytes)

173. [Amps] Stripline design (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Thu, 5 Jan 2012 01:38:06 +0000 (UTC)
Hi group, NHY to all! I am working on an amplifier mod and need some advice. I have a currently working 70cm stripline amp based on the 3cx400A7 tube. As everyone knows, that tube is getting rare and
/archives//html/Amps/2012-01/msg00046.html (8,599 bytes)

174. Re: [Amps] Stripline design (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Thu, 5 Jan 2012 21:38:05 +0000 (UTC)
Hi David, Thanks for the reply and the great information. I can put together some specifics and more pictuers of the inside of the deck, and using a copper foil wouldbe an easy way to test it. The 3c
/archives//html/Amps/2012-01/msg00069.html (10,525 bytes)

175. Re: [Amps] Stripline design (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Fri, 6 Jan 2012 00:06:27 +0000 (UTC)
I've had a casual interest in how striplines work for a while, but not to the point that I have started a detailed study. You've provied a great explanation. From what I can gather, the "stripline" i
/archives//html/Amps/2012-01/msg00074.html (14,036 bytes)

176. Re: [Amps] Stripline design (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Fri, 6 Jan 2012 02:53:31 +0000 (UTC)
Hi Gerald, I could use K1FO's design, but I already have a "nice" working unit. The K1FO won't physically fit in my RF chamber ( well it might with a hammer), and I just wanted to do something quick
/archives//html/Amps/2012-01/msg00076.html (11,542 bytes)

177. Re: [Amps] Stripline design (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Fri, 6 Jan 2012 13:08:06 +0000 (UTC)
Thanks to everyone for the really good discussion on this, I've learned a few things. If there is no visible moon this weekend, I'll likely tear into my amp and take some internal dimensions. It won'
/archives//html/Amps/2012-01/msg00087.html (9,244 bytes)

178. [Amps] 432 MHz stripline (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Tue, 24 Jan 2012 02:30:37 +0000 (UTC)
Hi gang, A few weeks ago I asked the group about modification to my 8874 stripline 432 MHz amplifier to replace it with a 3cx800. Well I made the modifications and extended just the very back portion
/archives//html/Amps/2012-01/msg00171.html (7,508 bytes)

179. Re: [Amps] 432 MHz stripline (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Tue, 24 Jan 2012 03:14:39 +0000 (UTC)
Hi Gerald, You've hit the nail on the head on why I asked the question. Every time I took the stripline cover off and put it back on I got different results. In fact, I have a suspician the original
/archives//html/Amps/2012-01/msg00174.html (11,889 bytes)

180. Re: [Amps] 432 MHz stripline (score: 1)
Author: Paul Decker <kg7hf@comcast.net>
Date: Thu, 26 Jan 2012 02:30:33 +0000 (UTC)
Thanks Dave, I'll give that a try my "return loss" meter is actually pc based and provides a sweep generator (AIMuhf) then graphs the results of the sweep so I can likely run a sweep and see which di
/archives//html/Amps/2012-01/msg00195.html (8,744 bytes)


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