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161. [AMPS] Tuned Input Circuit Q (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Tue, 9 Oct 2001 11:22:54 -0400
No, I "like" ANY network that provides a low impedance from cathode to ground for harmonics of the drive frequency at the cathode of the tube. It doesn't matter what that network is, as long as it b
/archives//html/Amps/2001-10/msg00230.html (9,410 bytes)

162. [AMPS] 3-500Z emission saturation (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Tue, 9 Oct 2001 16:56:09 -0400
Anyone who claims a 3-500Z starts to "saturate" at "c. 420 mA" clearly has no idea what he is saying, or is intentionally giving misinformation. Thoriated tungsten tubes typically begin to show emis
/archives//html/Amps/2001-10/msg00246.html (9,414 bytes)

163. [AMPS] Re: CW/SSB Tune Up (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Tue, 9 Oct 2001 20:48:44 -0400
Even if the metering system does not indicate peaks, it is generally good for geting optimum tuning on long pulses. The only requirement is the rise and fall be short compared to the flat time at th
/archives//html/Amps/2001-10/msg00254.html (9,801 bytes)

164. [AMPS] SB-220 cooling (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Fri, 12 Oct 2001 21:21:56 -0400
True example. I was working on a HV supply with a resonant choke, and got the choke on the low side or resonance. When I turned the supply on with a meter attached, it blew a 20 or 30kV rated test l
/archives//html/Amps/2001-10/msg00312.html (8,662 bytes)

165. [AMPS] Hand in the pocket? (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Mon, 15 Oct 2001 10:15:41 -0400
When I got zapped by the HV lead that flew up and attached itself to my wrist, I was standing on a HV blanket like the kind electric companies use on live power lines. I had one hand "in my pocket",
/archives//html/Amps/2001-10/msg00338.html (7,691 bytes)

166. [AMPS] Amp Drive Power(Long) (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Wed, 17 Oct 2001 03:21:05 -0400
Look at the reflected power. Subtract the reflected power from forward, and you have real power delivered to the load (neglecting the small cable and input circuit losses). It should not appear that
/archives//html/Amps/2001-10/msg00351.html (11,077 bytes)

167. [AMPS] Amp Drive Power(Long) (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Wed, 17 Oct 2001 09:33:51 -0400
The best way to look at this is with harmonic content required to make a wave some shape other than a sine wave. The waveform MUST have harmonics of the drive frequency to change waveshape during a
/archives//html/Amps/2001-10/msg00355.html (10,242 bytes)

168. [AMPS] Amp Drive Power(Long) (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Wed, 17 Oct 2001 21:23:24 -0400
Is it grid driven? Sure that is true, but it is obviously not the concern Jim has...unless he is using 75 ohm cable between a 50 ohm amp and his exciter. The radio's output impedance has nothing to
/archives//html/Amps/2001-10/msg00369.html (9,468 bytes)

169. [AMPS] Re: 8k ultra/ "tuned input" (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Thu, 18 Oct 2001 20:07:07 -0400
How do you get DC out of an RF amplifier? 73, Tom W8JI W8JI@contesting.com -- FAQ on WWW: http://www.contesting.com/FAQ/amps Submissions: amps@contesting.com Administrative requests: amps-REQUEST@co
/archives//html/Amps/2001-10/msg00387.html (8,602 bytes)

170. [AMPS] Calculating input impedance and drive requirements? (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Fri, 19 Oct 2001 15:11:01 -0400
Actually that question is too complex, because characteristic curves for GG 813's is almost certainly not available. The fastest and best (and probably only) thing is to measure the driving impedanc
/archives//html/Amps/2001-10/msg00402.html (7,413 bytes)

171. [AMPS] MEASURING FILAMENT VOLTAGE (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Mon, 22 Oct 2001 11:28:12 -0400
Normally you can just measure at the socket pins, if the socket has noticeable drop you need to change it or repair it anyway. If you want to temporarily measure at the pins, pull the tube. Use tefl
/archives//html/Amps/2001-10/msg00435.html (8,184 bytes)

172. [AMPS] Cleaning aluminum variable capacitors (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Mon, 22 Oct 2001 11:28:11 -0400
Clean it any way that does not leave any sharp points or scratched edges on the capacitor plate. Any sharp edge (even very very fine or small edges), burrs, or reduction of rounding of plate edges g
/archives//html/Amps/2001-10/msg00436.html (7,847 bytes)

173. [AMPS] HA-10 Warrior Parasitic Supressor Inductor Values (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Mon, 3 Sep 2001 11:00:29 -0400
That is NOT correct Ian. Bad enough that Rich says things without being fully aware what is going on! The feedback in the Warrior is from the anode, through a capacitor, through a phase inverting tr
/archives//html/Amps/2001-09/msg00032.html (11,318 bytes)

174. [AMPS] Heathkit Warrior (HA-10) questions (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Mon, 3 Sep 2001 20:49:38 -0400
Harvey, You should check the neutralization the way I described in my reply to Ian. It is safer and also works better. As for the low power, is filament voltage OK? Can you bring a lead out from the
/archives//html/Amps/2001-09/msg00045.html (7,289 bytes)

175. [AMPS] Another Tube Max Plate Current Question (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Mon, 3 Sep 2001 20:49:38 -0400
Tubes do not live happily for many years at 500mA, and then suddenly die if you run 20% more current. As a matter of fact, current has little if any effect on life as long as you don't exceed the pe
/archives//html/Amps/2001-09/msg00046.html (8,068 bytes)

176. [AMPS] HA-10 Warrior Parasitic Supressor Inductor Values (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Mon, 3 Sep 2001 20:49:37 -0400
Hi Ian, I'm not sure if all runs of the FL2100 do this, but the FL2100 I looked at takes a sample of RF after the pi-network and feeds it back to the input. Of course in that system the operating Q o
/archives//html/Amps/2001-09/msg00047.html (10,234 bytes)

177. [AMPS] HA-10 Warrior Parasitic Supressor Inductor Values (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Tue, 4 Sep 2001 19:58:29 -0400
I'd make sure I had a neutralizing system, and use a suppressor like the Ameritron AL811H uses if I was refurbishing a Warrior. There are two distinctly different stability problems with tubes like
/archives//html/Amps/2001-09/msg00060.html (13,372 bytes)

178. [AMPS] True Or Not True #2 (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Thu, 6 Sep 2001 21:50:38 -0400
Even 1dB is a huge increase when copying a signal near noise. The error rate changes considerably here when working CW, when I pick antennas that offer even 1dB more S/N ratio. Most S meters are in
/archives//html/Amps/2001-09/msg00090.html (9,193 bytes)

179. [AMPS] True Or Not True #2 (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Fri, 7 Sep 2001 07:10:09 -0400
The Radio Amateurs Handbook can not establish an industry "standard". Even if they tried, it would only be a standard if everyone used or attempted to use it. Most receiver use 3-5dB as the target.
/archives//html/Amps/2001-09/msg00101.html (10,668 bytes)

180. [AMPS] True Or Not True #2 (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Fri, 7 Sep 2001 20:11:16 -0400
Zero dB S/N is a very workable CW signal for good weak signal CW ops. Many people can even dig below zero dB S/N if the noise is "rough" noise. The reason is noise power is directly related to filte
/archives//html/Amps/2001-09/msg00112.html (8,284 bytes)


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