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References: [ +from:Ian: 2095 ] [ White: 4243 ]

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301. [AMPS] Floating Ground (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Wed, 4 Apr 2001 13:22:34 +0100; Although the article is associated with a specific commercial product, the general points are valid for all triode amplifiers. 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice' columnist; /archives//html/Amps/2001-04/msg00067.html (7,687 bytes)
302. [AMPS] ALPHA 77SX on 50Hz (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Fri, 6 Apr 2001 07:54:29 +0100; Interesting figures... so the total weight of the transformer increases as something like the square of the core cross-sectional area. Seems about right. And then the capacity of a blower with an AC; /archives//html/Amps/2001-04/msg00132.html (9,312 bytes)
303. [AMPS] ALPHA 77SX on 50Hz (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Fri, 6 Apr 2001 16:35:08 +0100; My "seems about right" was based on the notion that although the core cross-section would only need to be 20% larger, a core built from standard off-the-shelf laminations would probably be larger in; /archives//html/Amps/2001-04/msg00145.html (9,850 bytes)
304. [AMPS] MLA2500 and screen voltage for 4CX800. (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Wed, 11 Apr 2001 16:10:41 +0100; John did the measurements and faxed me the screen dumps. I prepared the bar charts and the web page on my site. A few additional points: 1. The "need" for good screen regulation will depend on the ty; /archives//html/Amps/2001-04/msg00254.html (12,671 bytes)
305. [AMPS] Zener screen supplies (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Fri, 13 Apr 2001 08:46:21 +0100; [...] You can't generalize either way on the basis of complexity alone. Complex circuits can offer design opportunities that don't exist in simple circuits; but they also have more to go wrong. In th; /archives//html/Amps/2001-04/msg00300.html (12,570 bytes)
306. [AMPS] Zener screen supplies (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Fri, 13 Apr 2001 19:53:54 +0100; My, you must have led a sheltered life... 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice' columnist for RadCom (RSGB) http://www.ifwtech.com/g3sek -- FAQ on WWW: http://www.contesting.c; /archives//html/Amps/2001-04/msg00302.html (9,145 bytes)
307. [AMPS] Zener screen supplies (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Sat, 14 Apr 2001 14:43:49 +0100; The MOV or gas tube at the screen terminal is actually the *first* line of defense because that is where the arc hits. Tom correctly identifies that the screen bypass capacitor in the socket is at le; /archives//html/Amps/2001-04/msg00324.html (11,731 bytes)
308. [AMPS] Zener screen supplies (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Sat, 14 Apr 2001 22:10:42 +0100; Not true, on two counts. 1. Sometimes the arc is due to an RF problem external to the tube, such as a high SWR. 2. Sometimes the arc isn't any kind of RF problem at all. Many of mine have been due to; /archives//html/Amps/2001-04/msg00343.html (10,852 bytes)
309. [AMPS] Zener screen supplies (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Mon, 16 Apr 2001 10:01:13 +0100; We are talking about power supplies, and the power supply doesn't care where the arc is. Only after you have provided a cathode bypass capacitor and re-wired the entire power supply. Although DC grou; /archives//html/Amps/2001-04/msg00361.html (11,383 bytes)
310. [AMPS] Zener screen supplies (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Mon, 16 Apr 2001 09:42:24 +0100; I see what you mean now. Oh, that one... sure, you always need that. I thought you meant another impedance between the screen and the screen supply, which would help to protect the supply. That may w; /archives//html/Amps/2001-04/msg00362.html (11,010 bytes)
311. [AMPS] Zener screen supplies (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Mon, 16 Apr 2001 15:12:45 +0100; Enough of these non-standard units! The last time I used the arc method to measure the length of the gap on a 4CX250, it was 1.0 earwig. 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice'; /archives//html/Amps/2001-04/msg00369.html (9,906 bytes)
312. [AMPS] Zener screen supplies (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Tue, 17 Apr 2001 11:23:22 +0100; Assuming that the arc strikes extremely rapidly, the rise time is going to be of the order of RC, where R is the glitch resistor and C is the bypass capacitance. That comes out to a few tens of nanos; /archives//html/Amps/2001-04/msg00387.html (10,190 bytes)
313. [AMPS] Zener screen supplies (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Tue, 17 Apr 2001 14:31:55 +0100; Never tried to measure it. Whole earwigs can crawl past the edge of the blower wheel, but craneflies are reduced to decimal fractions. 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice' co; /archives//html/Amps/2001-04/msg00392.html (9,272 bytes)
314. [AMPS] Zener screen supplies (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Tue, 17 Apr 2001 21:16:48 +0100; She's a softie. The other 55 million of us can do much worse than her... if sufficiently provoked. 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice' columnist for RadCom (RSGB) http://www; /archives//html/Amps/2001-04/msg00403.html (9,437 bytes)
315. [AMPS] RF deck cooling (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Sat, 21 Apr 2001 16:45:49 +0100; Blowing into the output compartment is standard practice on many VHF/UHF cavity amps that use "external anode" tubes - but not quite in the way you were thinking of doing it. If you can totally seal; /archives//html/Amps/2001-04/msg00453.html (9,088 bytes)
316. [AMPS] (no subject) (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Sat, 10 Mar 2001 00:09:15 +0000; The power output capabilities are actually very similar - as you'd expect because they are both 1.5kW dissipation tubes. The filament voltage, bias voltage, cathode impedance and drive requirements a; /archives//html/Amps/2001-03/msg00063.html (8,128 bytes)
317. [AMPS] Meter Protection for Drake L7 (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Sat, 10 Mar 2001 21:17:50 +0000; You're asking for two different things: protection against faults, and low errors due to current flowing through the diode in normal operation. Both depend on the voltage drops across the individual; /archives//html/Amps/2001-03/msg00074.html (9,088 bytes)
318. [AMPS] SB-220 Amplifiers and Garage Sales!! (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Tue, 27 Mar 2001 18:41:49 +0100; When this show was playing about two years ago, we went through all this stuff about equivalent series and parallel resistances and reactances: Rs, Rp, Xs, Xp and all their friends and relatives. You; /archives//html/Amps/2001-03/msg00284.html (9,243 bytes)
319. [AMPS] SB-220: Operate/Standby Switch (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Sun, 4 Feb 2001 09:32:20 +0000; The Eimac data sheet says "180 seconds minimum". The exact warmup time is a judgement call, even by Eimac. If you connect a high-resolution DVM across the heater, it acts as its own resistance thermo; /archives//html/Amps/2001-02/msg00099.html (12,943 bytes)
320. [AMPS] Coax as an RF choke?? (score: 147): Author: Ian White, G3SEK" <g3sek@ifwtech.com (Ian White, G3SEK); Date: Fri, 9 Feb 2001 23:55:22 +0000; Sure, it works fine. UT141 semi-rigid is OK at these currents, and you do not need a quarter-wave if you wind it into a coil. 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book' 'In Practice' columnist f; /archives//html/Amps/2001-02/msg00204.html (7,759 bytes)

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