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References: [ +from:mike.tubby@thorcom.co.uk: 47 ]

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21. [AMPS] mini Teflon coax, the white stuff (score: 1): Author: mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc. (Hons) G8TIC); Date: Tue, 12 Feb 2002 10:46:46 -0000; Skipp, I think the coax you're referring to is RG188 - approximately 3.3mm OD white Teflon/PTFE, 50 ohm. I have some here in the UK... but you should be able to find it more locally. Mike G8TIC/M0VH; /archives//html/Amps/2002-02/msg00102.html (8,872 bytes)
22. [AMPS] Thanks for BIRD meter info! (score: 1): Author: mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc. (Hons) G8TIC); Date: Tue, 12 Feb 2002 17:25:20 -0000; power. heat the is I have an even better spin on this... you can save even putting the short circuit on the outside and even needing RF drive to energise it! Disconnect the antennas, feeders, HF rig; /archives//html/Amps/2002-02/msg00112.html (9,639 bytes)
23. [AMPS] Bird peak reading meter? Slightly off topic (score: 1): Author: mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc. (Hons) G8TIC); Date: Tue, 12 Feb 2002 17:28:18 -0000; the meter (LM-324) Most possible If a using You might like to look at K0XP's web site at: http://www.qsl.net/k0xp/Technical/PEPMeter/PEPMeter.htm where you'll find details of a 'modern' PEP reading m; /archives//html/Amps/2002-02/msg00113.html (11,341 bytes)
24. [AMPS] found connectors but now : cable ? (score: 1): Author: mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc (Hons) G8TIC); Date: Tue, 29 Jan 2002 21:04:49 -0000; I used PET-100 connectors (horrid) and RG58 (okay) on my old W1SL 2m amp and 3-500Z on 6m. The PET-100 doesn't grip the RG58 very well and long-term can flex and cause whiskers of the braid to short; /archives//html/Amps/2002-01/msg00275.html (13,000 bytes)
25. [AMPS] 6m amp with 8877, blocking caps, etc. (score: 1): Author: mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc. (Hons) G8TIC); Date: Wed, 5 Dec 2001 15:28:11 -0000; All, I have a 8877 amplifier for 6m [the one which Steve G8GSK mentions in his postings] which has an Eimac 8877 tube manufactured in 1993 in it. The amp is to the GJ4ICD/G3WOS design. When initially; /archives//html/Amps/2001-12/msg00109.html (10,705 bytes)
26. [AMPS] Transformer Current ratings (score: 1): Author: Michael J. Tubby B.Sc. G8TIC" <mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc. G8TIC); Date: Sat, 15 Dec 2001 12:01:10 -0000; Do you mean 2A peak or continuous 100% duty cycle? What recitifier and smooting configuration? As Rich hints if the transformers have a significant secondary resistance (impedance) it is likely that; /archives//html/Amps/2001-12/msg00227.html (9,802 bytes)
27. [AMPS] Bypassing Screen of 4cx800a for 50 MHz (score: 1): Author: mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc. (Hons) G8TIC); Date: Tue, 18 Dec 2001 15:45:34 -0000; To: <amps@contesting.com> screen cathode Steve, Rich, et. al... Surely the best screen bypass technique for a Tetrode is to mount the tube such that the screen is at chassis (both DC and RF) and then; /archives//html/Amps/2001-12/msg00328.html (12,005 bytes)
28. [AMPS] Bypassing Screen of 4cx800a for 50 MHz (score: 1): Author: mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc. (Hons) G8TIC); Date: Wed, 19 Dec 2001 09:19:32 -0000; To: <amps@contesting.com> sometimes buy then it - also the Its true that the reactance of the cathode decoupling (or is it coupling hi hi :-) was considered a problem and the author of the 144MHz 199; /archives//html/Amps/2001-12/msg00338.html (11,946 bytes)
29. [AMPS] 4CX250B Tube differences (score: 1): Author: mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc. (Hons) G8TIC); Date: Fri, 2 Nov 2001 16:04:00 -0000; Wasn't the '250BC a "selected for low secondary emission" version? Mike G8TIC -- FAQ on WWW: http://www.contesting.com/FAQ/amps Submissions: amps@contesting.com Administrative requests: amps-REQUEST@; /archives//html/Amps/2001-11/msg00016.html (7,286 bytes)
30. [AMPS] HV connectors (score: 1): Author: mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc. (Hons) G8TIC); Date: Tue, 20 Nov 2001 16:22:07 -0000; of Got my RG400 second-hand in lengths about 20' long (ex-mil-spec. GPS antenna feeders for old Trimble GPS receivers used in helicoptors) with SMA connectors on - cost about £5.00 (USD $7.00); /archives//html/Amps/2001-11/msg00377.html (9,378 bytes)
31. [AMPS] Screen supply regluation??? (score: 1): Author: mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc. (Hons) G8TIC); Date: Mon, 26 Nov 2001 21:02:32 -0000; Yes, especially for SSB where the duty cycle is such that avg screen current is c. 20% of that for AØ operation. However, for tubes with a 400v screen, reverse screen current is often conside; /archives//html/Amps/2001-11/msg00434.html (8,837 bytes)
32. [AMPS] Screen supply & negative current???? (score: 1): Author: mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc. (Hons) G8TIC); Date: Wed, 28 Nov 2001 10:25:16 -0000; Randy, In a power Tetrode the conditions on the Screen change through the RF conduction cycle - causing current to flow into or out of the Screen (assuming that the voltage is kept constant). If you; /archives//html/Amps/2001-11/msg00453.html (10,865 bytes)
33. [AMPS] Amp Drive Power(Long) (score: 1): Author: mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc. (Hons) G8TIC); Date: Wed, 17 Oct 2001 12:28:05 +0100; Interesting tests but do you beleive the output of the Icom 775 to be 50R+0j without the tuner... bet it isn't and therefore you are actually looking at the complex network of: - output of radio - le; /archives//html/Amps/2001-10/msg00352.html (16,949 bytes)
34. Glitch protection (was Re: [AMPS] amazing doubletalk...) (score: 1): Author: mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc. (Hons) G8TIC); Date: Fri, 14 Sep 2001 16:54:19 +0100; Surely there are a range of causes for arcs in tube-based power amplifiers, for example when I was younger (much younger, like 20 years ago) my first W1SL 2 x 4CX250B amplifer for 144MHz had a poorly; /archives//html/Amps/2001-09/msg00248.html (12,710 bytes)
35. [AMPS] IMD (score: 1): Author: mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc. (Hons) G8TIC); Date: Tue, 18 Sep 2001 14:18:39 +0100; Has anyone disconnected the exciter stages of a TS2000 from the main PA and measured them seperately? Is it a case of good amplifier raising the levels of cr*p drive, the otherway round, or both? Th; /archives//html/Amps/2001-09/msg00309.html (12,500 bytes)
36. [AMPS] IMD (score: 1): Author: mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc. (Hons) G8TIC); Date: Tue, 18 Sep 2001 16:34:55 +0100; lies? But then there are transistors, transistors and transistors - for example, as well you probably know, there are the sorts of devices used in amateur radio products designed by so-called profes; /archives//html/Amps/2001-09/msg00323.html (10,659 bytes)
37. [AMPS] IMD (score: 1): Author: mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc. (Hons) G8TIC); Date: Tue, 18 Sep 2001 17:11:14 +0100; in example, FM for other Not sure about that relationship but I bet there is one similar to: cost = performance (eg. IMD) * power-output M -- FAQ on WWW: http://www.contesting.com/FAQ/amps Submissio; /archives//html/Amps/2001-09/msg00325.html (10,772 bytes)
38. Perfect keying waveform (was: Re: [AMPS] TS-2000) (score: 1): Author: mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc. G8TIC); Date: Sat, 4 Aug 2001 07:56:34 +0100; what one time control [snip] Surely the "perfect" keying shape for any rectangular pulse train (for that is what CW is) is a Gaussian? Not sin(x)/x or RC filtered? I recall (just about) from comms l; /archives//html/Amps/2001-08/msg00044.html (10,181 bytes)
39. [AMPS] Wanted: Alive 8877s (score: 1): Author: mike.tubby@thorcom.co.uk (Michael J. Tubby B.Sc. (Hons) G8TIC); Date: Tue, 21 Aug 2001 13:06:40 +0100; I would like to buy one or two fit and healthy 8877s for my 6m amplifier, in case one day (a) I can't get a new tube, (b) I have the unfortunate requirement to send a dead one to Rich. Anyone got any; /archives//html/Amps/2001-08/msg00253.html (6,854 bytes)
40. Re: [Amps] 4CX350A for VHF? (score: 1): Author: "Michael J. Tubby B.Sc. $Hons$ G8TIC" <mike.tubby@thorcom.co.uk>; Date: Thu, 28 Aug 2003 16:36:52 +0100; make a little desktop amp for 2M out of them but a quick look at Eimac's web page at the specs make me wonder if this this might be a bad idea. Further, web searches produce a mixed bag of success/f; /archives//html/Amps/2003-08/msg00062.html (8,146 bytes)

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