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261. [AMPS] close ratings (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Wed, 18 Jul 2001 05:33:40 -0400; That's right Peter. That is ONLY true when loading is correct for the amount of drive. You can easily have several times that voltage in an amplifier that isn't class A. I have a breadboard MOSFET a; /archives//html/Amps/2001-07/msg00204.html (7,763 bytes)
262. [AMPS] Setting the record straight--Dick Ehrhorn (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Wed, 18 Jul 2001 12:15:09 -0400; Everyone else in the world seems to share your and Dick's experience John. The only place parasitics cause tube failures is in the mind of the fellow who sells kits that "fix the problem". 73, Tom W; /archives//html/Amps/2001-07/msg00214.html (8,975 bytes)
263. [AMPS] construction of parasitics (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 20 Jul 2001 16:24:55 -0400; Hi Skipp, I have a serious question, and I think the answer would be of great use to many people. Can you share the formula you use in determining the amount of L and R required to stabilize an ampli; /archives//html/Amps/2001-07/msg00244.html (8,509 bytes)
264. [AMPS] Setting the record straight--Dick Ehrhorn (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Sat, 21 Jul 2001 12:18:40 -0400; The real thing that separates amps are the tubes. Tubes used at VHF and UHF typically have almost zero length grid leads because they are brought to a ring or flange. If you look at tubes that are p; /archives//html/Amps/2001-07/msg00252.html (10,809 bytes)
265. [AMPS] construction of parasitics (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Sun, 22 Jul 2001 15:45:21 -0400; It is the INTERNAL construction that determines arcing (voltage rating) not the case. The best solution is to buy a voltage rated component, unless you want to do tests. 73, Tom W8JI W8JI@contesting; /archives//html/Amps/2001-07/msg00276.html (8,248 bytes)
266. [AMPS] Re: The Big V Problem (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Mon, 23 Jul 2001 10:34:16 -0400; I checked everything here, and no V. At least I found none of the files on the Norton site, and my McAfee (current) detects nothing. These V writers need to find something more creative to do! 73, T; /archives//html/Amps/2001-07/msg00288.html (7,392 bytes)
267. [AMPS] Inductively Coupled VHF Parasitic Suppressor? (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 24 Jul 2001 15:56:30 -0400; Hi Todd, There are dozens of ways to solve a problem, so that might work in the few cases where anode impedance is controlled by the enclose and where that cavity resonance just happens to be at the; /archives//html/Amps/2001-07/msg00299.html (8,664 bytes)
268. [AMPS] FT100D driving Alpha 87a (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 27 Jul 2001 05:41:27 -0400; My main rig is an FT1000D. The FT1000D, unlike many rigs, has reasonably good ALC system. Mine certainly is fast enough to work well on SSB and CW. There is only a slight trace of overshoot if I run; /archives//html/Amps/2001-07/msg00324.html (8,868 bytes)
269. [AMPS] Water dielectric? (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 31 Jul 2001 10:11:43 -0400; When you look around and see the industry avoiding a method there is almost always a good reason. In this case they are probably concerned about loss of Q and heating of the component. Dissipation f; /archives//html/Amps/2001-07/msg00378.html (8,383 bytes)
270. [AMPS] continued Alpha work (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Sat, 2 Jun 2001 20:08:39 -0400; Skipp, All of that is a waste of time, if indeed he has high grid current AND high plate current at the same time. Open blocking caps cause low plate current and high grid current. Misaligned tanks c; /archives//html/Amps/2001-06/msg00019.html (9,123 bytes)
271. [AMPS] continued Alpha work (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 5 Jun 2001 08:48:32 -0400; The problem can be a breakdown problem in a component, or something in the auto-bias. That amp doesn't have zero signal quiescent current because of the auto bias. The amp might have multiple proble; /archives//html/Amps/2001-06/msg00040.html (9,556 bytes)
272. [AMPS] Filament voltage/bad advice (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Wed, 20 Jun 2001 11:07:34 -0400; Hi Bob, Harmful advice was presented in the Hint&Kinks section of July 2001 QST. One should NEVER *under any circumstance* reduce the filament voltage of a indirectly heated tube below the tube or eq; /archives//html/Amps/2001-06/msg00185.html (10,270 bytes)
273. [AMPS] Review of Antenna Tuner from Dayton (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Wed, 20 Jun 2001 12:03:52 -0400; Well Jon, it might be advisable to spend time looking at voltages in T network tuners. If you run the numbers, you'll see the largest problems causing arcing are excessive Q on the low bands. Excess; /archives//html/Amps/2001-06/msg00186.html (12,069 bytes)
274. [AMPS] Review of antenna tuner from Dayton (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Wed, 20 Jun 2001 16:14:05 -0400; That's how tuners are supposed to be built, with one possible exception. I don't know what that exact circuit is, but moving the balun to the input of the tuner does NOT help balance, or make the ba; /archives//html/Amps/2001-06/msg00197.html (10,881 bytes)
275. [AMPS] Review of Antenna Tuner from Dayton (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Thu, 21 Jun 2001 00:26:03 -0400; Unfortunately wider spacing increases voltage at the same rate as the wider spacing increases voltage rating when as you are using far less than optimum capacitance. You really gain nothing, for a c; /archives//html/Amps/2001-06/msg00212.html (10,537 bytes)
276. [AMPS] Filament voltage/bad advice (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Thu, 21 Jun 2001 00:26:03 -0400; Did you run several sample comparisons, or is this just an opinion based on one tube? Doing that with an indirectly heated tube, like an 8877, is a disaster waiting to happen. Reducing voltage on a; /archives//html/Amps/2001-06/msg00213.html (9,203 bytes)
277. [AMPS] filament cutback (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Thu, 21 Jun 2001 13:28:23 -0400; The problem everyone seems to miss, and it certainly is a problem, is that amateurs have varying drive power from band to band. Amateur operators tune the amplifier differently from time-to-time and; /archives//html/Amps/2001-06/msg00238.html (8,683 bytes)
278. [AMPS] amp switching control (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Wed, 27 Jun 2001 10:24:58 -0400; The MFJ 495 CW keyer does that with CW. It has a PTT output that closes the moment the key is closed, but the actual CW to the radio is delayed an adjustable amount. The main idea was a CW contestin; /archives//html/Amps/2001-06/msg00294.html (7,537 bytes)
279. [AMPS] AL-811H and PEP Question (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 29 Jun 2001 14:46:04 -0400; Later MFJ antenna tuners have a place on the metering board to add a single transistor and a couple other components that will make the peak reading function work almost perfectly. It will read with; /archives//html/Amps/2001-06/msg00330.html (7,759 bytes)
280. [AMPS] More MLA2500 conversion questions (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 1 May 2001 19:50:34 -0400; What really happens is at the time when the grid is closest to being overdriven or overdriven, the gain goes up. When the drive is low with plenty of headroom, the drive power goes down more. Scope; /archives//html/Amps/2001-05/msg00016.html (7,776 bytes)

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