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1. [AMPS] QBL 5/3500 (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Sat, 18 Mar 2000 20:17:31 +0200; Hi all, for what it is worth - the QBL 5/3500 is a an updated version version of an old Mullard tube, the QY5-3000A. The two are practically identical and I have the original Mullard data book publis; /archives//html/Amps/2000-03/msg00809.html (11,996 bytes)
2. [AMPS] 3/2 law, DAF, other musings (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Thu, 23 Mar 2000 19:58:39 +0200; To: <amps@contesting.com> However you need to ask yourself what happens to the even harmonic power (energy) when it arrives at the harmonic filter? If the filter is an absorptive type then the vast m; /archives//html/Amps/2000-03/msg00930.html (8,734 bytes)
3. SV: SV: [AMPS] Final.. (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Tue, 4 Jan 2000 18:42:26 +0200; Now you got me!!!!! How the hell can one develop power into a pure reactance????? Surely the grid of a tube biased for AB1 is resistive? John ZS5JF -- FAQ on WWW: http://www.contesting.com/ampsfaq.ht; /archives//html/Amps/2000-01/msg00080.html (9,165 bytes)
4. [AMPS] 50 MHz Amp Details (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Tue, 4 Jan 2000 18:42:59 +0200; I have to agree with Ian about the "supply" of Russian tubes. I was at Friederichschafen Hamradio exhibition in June and spoke to several HA's who had tea chests full of tubes and complete amplifiers; /archives//html/Amps/2000-01/msg00081.html (10,916 bytes)
5. [AMPS] More and More and More and More - drive derived screen potential (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Mon, 20 Dec 1999 16:16:30 +0200; May I add my 2cents worth. Some causes of imd are not in fact due to the amplifier! In the G2DAF original circuit the impedance "seen" by the driver is approx. 300 ohms in order to develop sufficeint; /archives//html/Amps/1999-12/msg00274.html (13,435 bytes)
6. [AMPS] Reduction Drive (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Tue, 16 Nov 1999 18:25:17 +0200; Hi Mike, Grease is a mixture of oil and soap! Soap's main constitutients are caustic soda, lanolin or some-other fatty animal or synthetic oily material. Grease and plastic often don't exist well tog; /archives//html/Amps/1999-11/msg00343.html (10,709 bytes)
7. [AMPS] 2 tone intermod test (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Tue, 23 Nov 1999 22:08:22 +0200; Hi Dave, I would like to second Rich's comments and just mention that the subject was aired extensively a while back on this list. G2DAF amplifiers et al. Ian White G3SEK and others (myself included); /archives//html/Amps/1999-11/msg00448.html (11,022 bytes)
8. [AMPS] 2 tone intermod test (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Wed, 24 Nov 1999 19:29:37 +0200; Hi Dave & all, I didn't say the "tones don't change fast enough", rather that the stabiliser circuits tend to "dc restore" the complex waveform and therefore don't follow the input correctly. Inciden; /archives//html/Amps/1999-11/msg00461.html (15,435 bytes)
9. [AMPS] Re: Our CB Brethren! (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Sat, 16 Oct 1999 19:02:38 +0200; Yep, plenty used at Marconi Communications in Chelmsford where they made the high power AM broadcast transmitters. Ask Peter G3RZP. I visited there once whilst they were testing a 1,5MW AM transmitte; /archives//html/Amps/1999-10/msg00518.html (9,016 bytes)
10. [AMPS] Alminum Capacitor (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Wed, 15 Sep 1999 18:59:12 +0200; No sir - off line switchers need large input smoothing caps for 2 reasons. 1. To hold up the supply for several dropped mains cycles. 2. To reduce the ripple on the raw DC to prevent sub-harmonic ope; /archives//html/Amps/1999-09/msg00124.html (8,773 bytes)
11. [AMPS] 3CX1500M7 wanted (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Tue, 10 Aug 1999 19:01:13 +0200; A local ham has asked me to try and find one or two 3CX1500M7 tubes for his amplifier. Can anyone point me to a source of good pulls or secondhand tubes? John ZS5JF -- FAQ on WWW: http://www.contesti; /archives//html/Amps/1999-08/msg00185.html (6,589 bytes)
12. [AMPS] Re:(AMPS) sb-200 troubles (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Wed, 11 Aug 1999 18:49:54 +0200; Not in my amplifiers! John ZS5JF -- To: <amps@contesting.com> -- FAQ on WWW: http://www.contesting.com/ampsfaq.html Submissions: amps@contesting.com Administrative requests: amps-REQUEST@contesting.c; /archives//html/Amps/1999-08/msg00205.html (9,946 bytes)
13. [AMPS] Safety RF choke (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Thu, 12 Aug 1999 18:57:36 +0200; Phil - your best solution is to connect a shorted 1/4 wave coaxial stub across the output connector. For 50 MHz the length will be approx. 995mm of RG58/U cable. If you are feeling adventurous you ca; /archives//html/Amps/1999-08/msg00244.html (9,950 bytes)
14. [AMPS] info on tubes required (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Thu, 26 Aug 1999 17:54:40 +0200; A friend has been offered some replacement tubes for his HB amp. The amp runs two 3-500Z but recently one has developed a problem. He has been offered two new tubes but these are 3-750Z. I have never; /archives//html/Amps/1999-08/msg00316.html (7,320 bytes)
15. [AMPS] info on tubes required (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Sat, 28 Aug 1999 16:42:41 +0200; Thanks to all who responded to my query. It seems the tubes may be TB3/750 which are similar to the 3-500Z. I have passed on the info to the ham concerned. Once again tks. John ZS5JF -- To: <amps@con; /archives//html/Amps/1999-08/msg00334.html (8,370 bytes)
16. [AMPS] Test - ignore (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Fri, 2 Jul 1999 16:17:10 +0200; Is there anyone out there? -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@contesting.com Administrative requests: amps-REQUEST@contesting.com Problems: owner-amps@contesting.c; /archives//html/Amps/1999-07/msg00012.html (6,516 bytes)
17. Fw: [AMPS] go figure/Murata (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Fri, 2 Jul 1999 18:12:03 +0200; -- To: <amps@contesting.com> 1MHz, To: <amps@contesting.com> -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@contesting.com Administrative requests: amps-REQUEST@contesting.com; /archives//html/Amps/1999-07/msg00014.html (9,794 bytes)
18. [AMPS] Murata capacitors (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Fri, 2 Jul 1999 18:16:35 +0200; 1MHz, > 5.9KVA @ 10MHz and 5.4KVA @ 30MHz. (KVA is approx. equal to KW at lowish frequencies) John ZS5JF -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@contesting.com Adminis; /archives//html/Amps/1999-07/msg00016.html (8,009 bytes)
19. [AMPS] PS diode equalizing (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Sun, 4 Jul 1999 10:03:00 +0200; The resistors and caps don't really force voltage sharing as the values are too high, however they do remove the high frequency transients caused when the diodes switch and reduce RFI from the rectif; /archives//html/Amps/1999-07/msg00031.html (9,360 bytes)
20. [AMPS] SMPS a la QEX (score: 1): Author: johnf@futurenet.co.za (John Fielding); Date: Thu, 8 Jul 1999 20:05:07 +0200; I would be very interested to know where the original author got his Schottky diodes for this psu as I have been lately perusing all the manufacturers data for such animals. The highest voltage types; /archives//html/Amps/1999-07/msg00147.html (12,013 bytes)

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