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141. [AMPS] parasitics (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Fri, 22 Aug 1997 12:23:28 +0000; To: <amps@contesting.com> Good example Peter. Higher series resistance almost always decreases high frequency response or gain. When I design a VHF suppressor, I try for a series resistance that dom; /archives//html/Amps/1997-08/msg00166.html (7,747 bytes)
142. [AMPS] HF2500 grid current readings (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Mon, 25 Aug 1997 09:40:06 +0000; To: <amps@contesting.com> You could have flakey tubes, or it could be something heating in the PA. Does it behave exactly the same way on all bands? If so, it is likely the tubes. If it behaves diff; /archives//html/Amps/1997-08/msg00180.html (10,435 bytes)
143. [AMPS] Amps in Sept QST (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Tue, 26 Aug 1997 21:38:37 +0000; To: <amps@contesting.com> Not by as much as you think. All Eimac and commercial specs use dB below ONE TONE while the ARRL uses dB below PEP. So the numbers are really: AL800H -43 dB third order, -4; /archives//html/Amps/1997-08/msg00190.html (9,252 bytes)
144. [AMPS] Parasitics in a VHF Amplifier? (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 27 Aug 1997 07:40:18 +0000; To: <amps@contesting.com> There usually isn't even a need at HF with that tube Bill, if the grid is properly grounded. Tubes that use a cone type grid connection and a short grid length, when ground; /archives//html/Amps/1997-08/msg00198.html (10,165 bytes)
145. [AMPS] Amps in Sept QST (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 27 Aug 1997 10:17:53 +0000; Hi Carl, I wish the ARRL would go back to the same standard the rest of the world uses. In a phone conversation, they said IMD deteriorated to the 30 odd dB range. They measured IMD on 14 MHz, and on; /archives//html/Amps/1997-08/msg00203.html (9,066 bytes)
146. [AMPS] CENTURION HELP (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 27 Aug 1997 21:40:09 +0000; The line cord DC resistance should be low. Does the ten tec warm up the tubes BEFORE applying HV to give them a chance to de-gas? Did you try disconnected the anode leads and applying power to see i; /archives//html/Amps/1997-08/msg00214.html (8,506 bytes)
147. [AMPS] Amps in Sept QST (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 27 Aug 1997 21:40:08 +0000; Nope, they do what they want to do. All that stuff about manufacturer's influence is sour grapes. I always use the conventional method in spec sheets. The AL-800H is speced at 30 some dB if I recall; /archives//html/Amps/1997-08/msg00215.html (9,647 bytes)
148. [AMPS] QST Review... (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 27 Aug 1997 22:39:17 +0000; Not correct. Spurious and harmonics are either harmonics or oscillations, and are usually measured with a single tone carrier. IMD results from modulation products, and are generally measure with a; /archives//html/Amps/1997-08/msg00216.html (7,512 bytes)
149. [AMPS] CENTURION HELP (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 27 Aug 1997 22:39:17 +0000; Actually two manufacturers tried and abandoned the nichrome. Neither manufacturer noted any improvement in field service. The Ten Tec tube problems were related to the lack of grid protection, and o; /archives//html/Amps/1997-08/msg00217.html (8,658 bytes)
150. [AMPS] Kenwood TL922 help please (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Fri, 29 Aug 1997 09:47:55 +0000; That's a common cause Jack. Another common cause is an antenna system fault, or incorrect loading. By far the most common cause of tank arcing is improper tuning, or a sudden lack of proper load. Wh; /archives//html/Amps/1997-08/msg00238.html (10,091 bytes)
151. [AMPS] CENTURION HELP (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Fri, 29 Aug 1997 09:47:56 +0000; The waveform is not a sine wave, so RMS voltage does not apply. You actually would have to do a Fourier analysis to determine the effective voltage G-K voltage. Eimac, in their literature, gives a g; /archives//html/Amps/1997-08/msg00239.html (10,071 bytes)
152. [AMPS] 8877s (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 2 Jul 1997 09:38:11 +0000; To: <amps@contesting.com> Marv, I tried e-mailing this to you, but it bounced. 73, Tom W8JI -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@contesting.com Administrative reque; /archives//html/Amps/1997-07/msg00001.html (7,986 bytes)
153. [AMPS] IC-706 output power spike: AMP KILLER??? (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Thu, 3 Jul 1997 07:50:29 +0000; If you think it's bad on the slower response Yaesu meter, you should see the spikes on my sample and hold storage power meter that only requires a few RF cycles to read peak power! My 706, with a 15; /archives//html/Amps/1997-07/msg00006.html (9,254 bytes)
154. [AMPS] SB-220 C4 failure (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Mon, 7 Jul 1997 08:04:55 +0000; The very small power demand of the bias supply (about 12 watts) would not greatly affect the core losses of a transformer already delivering 160 watts to a resistive load. The half wave rectifier is; /archives//html/Amps/1997-07/msg00017.html (9,493 bytes)
155. [AMPS] a few questions... (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Tue, 8 Jul 1997 09:38:50 +0000; To: <amps@contesting.com> It is probably a valid method of estimating transformer ESR, but you have to be VERY careful since leakage reactance will cause voltage and current to be out-of-phase. That; /archives//html/Amps/1997-07/msg00029.html (8,996 bytes)
156. [AMPS] SB-220 C4 failure (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Tue, 8 Jul 1997 20:48:06 +0000; To: <amps@contesting.com> That's correct Carl. Inrush was never a part of the concern. It wasn't until 1970 or so that inrush became the curse of the 220, causing arcs and pops and snaps and blowing; /archives//html/Amps/1997-07/msg00032.html (10,293 bytes)
157. [AMPS] SB-220 C4 failure (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 9 Jul 1997 09:03:15 +0000; To: <amps@contesting.com> Rich replied: Really? Doesn't the TL-922 use a series filament string?? I worked for Heath, and was involved in modernization of the SB-220 series. That made all engineerin; /archives//html/Amps/1997-07/msg00036.html (11,373 bytes)
158. [AMPS] Re: transformers (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Wed, 9 Jul 1997 20:19:38 +0000; To: <amps@contesting.com> My question was"does the TL-922 use a series or parallel filament circuit?". You stated the only difference was the transformer "style". . The flux leakage, in a transforme; /archives//html/Amps/1997-07/msg00041.html (10,985 bytes)
159. [AMPS] Grid capacitors (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Thu, 10 Jul 1997 10:48:14 +0000; Someone indicated removing the small mica's from the control grids to ground in the SB-220 would be harmful for stability. Actually the opposite is true. The series caps increase the anode to cathode; /archives//html/Amps/1997-07/msg00043.html (11,667 bytes)
160. [AMPS] Grid capacitors (score: 1): Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net); Date: Thu, 10 Jul 1997 22:50:03 +0000; To: <amps@contesting.com> Carl, I know you get upset with technical explanations, but let me try to explain this. I'll try to keep it simple. That circuit was a mistake. Bill Orr made great efforts; /archives//html/Amps/1997-07/msg00045.html (19,067 bytes)

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