- 221. Re: [Amps] Henry 3K trouble (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Wed, 01 Nov 2006 07:47:12 +0000
- Yes, two of the diodes don't have a function in this arrangement but I can't see that they do any harm either. I think it's a component where overkill is good and a bridge is a cheap way of getting a
- /archives//html/Amps/2006-11/msg00031.html (8,929 bytes)
- 222. Re: [Amps] Mega Amplifier? (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Sun, 05 Nov 2006 07:54:38 +0000
- That's right - it's a distributed line amp. Depending on the application, it's normal to run the valves in class A at 50-100W max. each. Steve _______________________________________________ Amps mai
- /archives//html/Amps/2006-11/msg00072.html (7,468 bytes)
- 223. Re: [Amps] FW: Zener Bias Replacement (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Tue, 07 Nov 2006 22:45:39 +0000
- How does a smaller diode with a big transistor fare (for example, see the very bottom of http://i5uxj-2.cln.it/amp/schemi/w6sai/w6sai.html) - or a big transistor with a TL431 as in the G3SEK 'triode
- /archives//html/Amps/2006-11/msg00112.html (7,797 bytes)
- 224. Re: [Amps] 20m RF deck using 2 GI7B's (score: 1)
- Author: "Steve Thompson" <g8gsq@eltac.co.uk>
- Date: Wed, 29 Nov 2006 13:06:24 +0000
- I'm sure there are designs to be found on the web which could be cut back to remove all the bandswitching and give you something to work from. My worry is that 3.5kV is very high for GI7s. If you hav
- /archives//html/Amps/2006-11/msg00272.html (7,172 bytes)
- 225. Re: [Amps] Elecraft amplifiers (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Mon, 11 Dec 2006 16:53:01 +0000
- Looks nice, but why do folks insist on plastering so much thermal grease everywhere? It's only marginally better than air at conducting heat and the trick is to use the absolute minimum needed. More
- /archives//html/Amps/2006-12/msg00065.html (6,680 bytes)
- 226. [Amps] Error - safety issue (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Sun, 24 Dec 2006 16:06:03 +0000
- A while ago there was a discussion about replacing a meter protection diode. I suggested using a 35A bridge, using the ac connections to give 'back to back' diodes so polarity didn't matter. A very i
- /archives//html/Amps/2006-12/msg00207.html (6,498 bytes)
- 227. Re: [Amps] Error - safety issue (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Sun, 24 Dec 2006 18:59:30 +0000
- Neater! The two diode version suited my last situation where the metering ran at 1V fsd. Cheers, Steve _______________________________________________ Amps mailing list Amps@contesting.com http://lis
- /archives//html/Amps/2006-12/msg00209.html (6,922 bytes)
- 228. Re: [Amps] Alpha 87a (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Tue, 02 Jan 2007 08:04:07 +0000
- Without time to do any calculations, here's a guess: The cathode current waveform contains a lot of harmonic energy due to it's 'spikey' waveform. A low Q input network means does not fully isolate t
- /archives//html/Amps/2007-01/msg00015.html (8,713 bytes)
- 229. Re: [Amps] RK65/5D23 tetrode (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Sat, 13 Jan 2007 07:40:51 +0000
- And a fag is something you smoke, garters hold mens socks up and suspenders are ladies underwear.... Steve _______________________________________________ Amps mailing list Amps@contesting.com http:
- /archives//html/Amps/2007-01/msg00116.html (7,047 bytes)
- 230. Re: [Amps] BAMA - somewhat OT (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Sun, 14 Jan 2007 16:10:59 +0000
- A note from http://bama.edebris.com/manuals/ Notes: regsvr32.exe /u msieftp.dll Steve _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com
- /archives//html/Amps/2007-01/msg00140.html (7,912 bytes)
- 231. Re: [Amps] Uncluttering 3CX800A7 socket wiring (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Tue, 16 Jan 2007 10:19:47 +0000
- Increased inductance in the grid lead might not make a measureable difference at hf, but will decrease vhf stability. Look out for the p word. I doubt that multiple cathode connections matter at hf.
- /archives//html/Amps/2007-01/msg00169.html (7,457 bytes)
- 232. Re: [Amps] EIMAC (8877 TYPE) TUBES FOR SALE (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Wed, 17 Jan 2007 20:01:07 +0000
- One small thing - they are a little bit taller than a standard 8877 so beware if there's anything immovable or critical around the anode connection. Steve ____________________________________________
- /archives//html/Amps/2007-01/msg00176.html (7,690 bytes)
- 233. Re: [Amps] 813 Filament Transformer (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Wed, 24 Jan 2007 12:27:01 +0000
- Either should work fine - it's fairly uncritical. I used a pair of 4.5V 50VA transformers - 4.5V is a common stock voltage over here - which also provides a convenient centre tap. Don't forget to rem
- /archives//html/Amps/2007-01/msg00244.html (7,097 bytes)
- 234. Re: [Amps] power supply transformer (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Thu, 25 Jan 2007 19:13:48 +0000
- You could keep an eye open for high current 48V switching psus which tend to be relatively cheap. Most will wind up at least 10% on the output voltage, then stack two in series. Steve _______________
- /archives//html/Amps/2007-01/msg00261.html (6,688 bytes)
- 235. Re: [Amps] Bad tubes from ebay, update (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Sun, 28 Jan 2007 08:00:56 +0000
- I think it's worth considering the context of the 500hrs. I suspect it's heavy duty, adverse conditions as these things were primarily for a military/airborne market. There's nothing fragile about th
- /archives//html/Amps/2007-01/msg00283.html (8,741 bytes)
- 236. Re: [Amps] 3CX1500A7 VS 3CPX1500A7 (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Sun, 28 Jan 2007 21:40:19 +0000
- There's a specific note in the 'CPX data sheet about heater voltage - basically recommending operation at 5V unless peak current above 24A (very short pulses) is needed. With 5.5V up to 50A peak is a
- /archives//html/Amps/2007-01/msg00305.html (7,279 bytes)
- 237. Re: [Amps] 2 meter 8877/3cx1500A7 (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Mon, 29 Jan 2007 07:45:54 +0000
- check out searches for K1AGB and YU1AW, also the anode circuit from http://www.g1ogy.com/www.n1bug.net/tech/4cx1000a/2m1500simple.html which should be useable with tweaks. Steve PS for anyone interes
- /archives//html/Amps/2007-01/msg00310.html (7,877 bytes)
- 238. Re: [Amps] variable caps (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Tue, 30 Jan 2007 16:34:00 +0000
- It depends on several factors, including altitude, humidity and surface finish. For 'normal' conditions I use 1kV/mm (25V/.001") as a guide for dc and hf, half that at vhf. Steve ____________________
- /archives//html/Amps/2007-01/msg00331.html (6,649 bytes)
- 239. Re: [Amps] Grid Current Metering FL-2100B (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Thu, 01 Feb 2007 08:40:00 +0000
- 2.7V and 160mA implies a resistance of 16.8 ohms - at first sight it looks like the current is flowing equally through both 33R resistors. Have you checked all the decoupling caps? Steve ____________
- /archives//html/Amps/2007-02/msg00000.html (6,963 bytes)
- 240. Re: [Amps] RE : triode gi-7bt repalce gi-46b ?? (score: 1)
- Author: Steve Thompson <g8gsq@eltac.co.uk>
- Date: Mon, 05 Feb 2007 08:33:29 +0000
- Certainly - especially with the limited loading control. Steve _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
- /archives//html/Amps/2007-02/msg00047.html (6,916 bytes)
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