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References: [ +from:gm3sek@ifwtech.co.uk: 471 ]

Total 471 documents matching your query.

241. Re: [Amps] Heathkit Warrior High Plate Current (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Wed, 22 Oct 2008 07:38:45 +0100
Don't even plug the power cord into the mains! There is a better, much safer way to do it. Working with a completely 'dead' amplifier, you can connect a small external power supply to deliver an accu
/archives//html/Amps/2008-10/msg00092.html (8,657 bytes)

242. Re: [Amps] Fwd: rx noise? (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Tue, 9 Dec 2008 08:39:07 +0000
Glad you found the problem, Dave. By coincidence(?) someone recently found a similar problem with a 78xx in a GaAsFET preamp that had been OK for years, but then decided to become unstable. Any thoug
/archives//html/Amps/2008-12/msg00164.html (9,417 bytes)

243. Re: [Amps] Fwd: rx noise? (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Tue, 9 Dec 2008 14:31:51 +0000
This came from a source I would trust - an experienced moonbouncer who keeps a very close watch on his noise level, and immediately noticed when that level increased. The e-mail exchange was only cop
/archives//html/Amps/2008-12/msg00170.html (9,302 bytes)

244. Re: [Amps] Tetrode Boards Grounding Scheme (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Wed, 7 Jan 2009 16:45:54 +0000
It helps to keep the leads between the two control boards reasonably short. If you use rather heavier wire for the CATHODE/CHASSIS bonding, this helps to prevent nuisance tripping of the protection c
/archives//html/Amps/2009-01/msg00038.html (9,672 bytes)

245. Re: [Amps] Glitch Resistor (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Mon, 2 Feb 2009 18:14:07 +0000
If they mean to use it as a fuse instead of a resistor, then NO. A fuse provides no current limiting until *after* it has blown. In the time it takes for a fuse to blow (which depends on the size of
/archives//html/Amps/2009-02/msg00032.html (8,728 bytes)

246. Re: [Amps] Glitch Resistor (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Wed, 4 Feb 2009 12:06:47 +0000
That is "the next level" of protection, beyond the simple glitch resistor and fuse/breaker. There are some classic papers by RCA involving thyratron or ignitron tubes, and also a modern thyristor des
/archives//html/Amps/2009-02/msg00059.html (12,411 bytes)

247. Re: [Amps] Fw: Tony King Bias board (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Fri, 13 Feb 2009 07:31:05 +0000
Very sorry indeed to hear that. Tony was a great guy and we exchanged many e-mails. Tony was "Mr GS35b of the Western World" and I do hope the information on his website can be preserved in his memor
/archives//html/Amps/2009-02/msg00405.html (7,539 bytes)

248. Re: [Amps] One more dumb question... (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Sun, 15 Feb 2009 08:37:55 +0000
I may think about his later, but right now is absolutely NOT the time. -- 73 from Ian GM3SEK http://www.ifwtech.co.uk/g3sek/boards _______________________________________________ Amps mailing list Am
/archives//html/Amps/2009-02/msg00467.html (7,402 bytes)

249. Re: [Amps] Remote power supply question (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Wed, 18 Feb 2009 19:48:30 +0000
Well, you could always try Radcom! The March issue (arriving any day now) winds up a three-part series on exactly this topic. Unfortunately the articles are only accessible to RSGB members, but there
/archives//html/Amps/2009-02/msg00551.html (8,849 bytes)

250. Re: [Amps] Remote power supply question (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Thu, 19 Feb 2009 07:42:12 +0000
If the PSU has the safety interlock and the coaxial HV+ connection with a grounded shield, and also uses purpose-designed coaxial HV connectors that don't allow finger contact to an open plug or soc
/archives//html/Amps/2009-02/msg00555.html (9,472 bytes)

251. Re: [Amps] MFJ Analyzer for adjusting matching network... (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Sat, 21 Feb 2009 16:51:58 +0000
A small amount of inductance won't matter in this situation, because the resistance value (1-2k) will be at least 100x higher than the inductive reactance. Film resistors are manufactured by depositi
/archives//html/Amps/2009-02/msg00611.html (9,088 bytes)

252. Re: [Amps] "Big Iron" transformer source in UK? (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Sun, 1 Mar 2009 08:16:57 +0000
There are two in: http://tinyurl.com/ukcomponents (go to the page and use your browser to find "transformers"). SP Wound Components are excellent for small custom transformers - they made the multi-w
/archives//html/Amps/2009-03/msg00000.html (8,904 bytes)

253. Re: [Amps] "Big Iron" transformer source in UK? (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Sun, 1 Mar 2009 09:10:37 +0000
The point I was making is that - for solid technical reasons - the "headline" kVA rating of the transformer needs to be significantly higher than the DC input to the amplifier, which in turn needs to
/archives//html/Amps/2009-03/msg00003.html (8,679 bytes)

254. Re: [Amps] "Big Iron" transformer source in UK? (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Sun, 1 Mar 2009 10:20:29 +0000
Sorry, I forgot to post the link: http://www.ifwtech.co.uk/g3sek/in-prac/best-of.htm#psud This page includes a link to download the program, and some HV PSU related support files. -- 73 from Ian GM3
/archives//html/Amps/2009-03/msg00005.html (8,698 bytes)

255. Re: [Amps] HV Divider (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Sun, 1 Mar 2009 20:25:26 +0000
So you have a voltage divider with 10M in the top leg and two 100k resistors in parallel (for safety) at the bottom. So the no-load voltage at the divider tap has got to be 2380V x 50k / (10M + 50k)
/archives//html/Amps/2009-03/msg00026.html (10,045 bytes)

256. Re: [Amps] HV Divider (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Sun, 1 Mar 2009 20:36:40 +0000
Apparently no. Scott reports an open-circuit resistor from B-minus to ground. Having fixed that, he's now seeing 11.68V from the divider, which is within 1.4% of the expected value. Many thanks to wh
/archives//html/Amps/2009-03/msg00028.html (8,678 bytes)

257. Re: [Amps] caps across rectifier diodes (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Tue, 3 Mar 2009 12:10:05 +0000
Oh, you're going to be sorry you asked this... Go to the Amps Archives at <http://tinyurl.com/c5knt9> and then keep clicking and reading "next in thread". We beat it to death but the issues and answe
/archives//html/Amps/2009-03/msg00090.html (8,417 bytes)

258. Re: [Amps] caps across rectifier diodes (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Tue, 3 Mar 2009 16:12:58 +0000
How much were you over-designing on the nominal PIV? -- 73 from Ian GM3SEK _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/li
/archives//html/Amps/2009-03/msg00099.html (9,420 bytes)

259. Re: [Amps] caps across rectifier diodes (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Tue, 3 Mar 2009 22:08:06 +0000
Maybe we should also be asking how that hash got into our receivers? Was it radiated through space or conducted along wiring - and where was the shielding and decoupling to prevent that? One feature
/archives//html/Amps/2009-03/msg00106.html (9,882 bytes)

260. Re: [Amps] caps across rectifier diodes (score: 1)
Author: Ian White GM3SEK <gm3sek@ifwtech.co.uk>
Date: Wed, 4 Mar 2009 11:17:51 +0000
Somewhere in Germany, one electric train doesn't run on time any more. -- 73 from Ian GM3SEK _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contest
/archives//html/Amps/2009-03/msg00113.html (9,305 bytes)


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