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References: [ +from:4cx250b@miamioh.edu: 327 ]

Total 327 documents matching your query.

241. Re: [Amps] Choke anomoly (score: 1)
Author: Jim Garland <4cx250b@miamioh.edu>
Date: Mon, 12 Nov 2018 17:27:22 -0700
Hmm, I wouldn't have said exactly that a choke is a constant current device, but I get where Bill is headed. Choke input filters resist changes in current because the choke inductance L induces a bac
/archives//html/Amps/2018-11/msg00049.html (10,194 bytes)

242. Re: [Amps] High temp magnet wire? (score: 1)
Author: Jim Garland <4cx250b@miamioh.edu>
Date: Tue, 4 Dec 2018 10:09:29 -0700
I believe Bill is correct. However, since K3LR's intended use is to repair a bad monoband 40m plate choke, the temperature specifications of the wire are not important. I'm sure Bill would agree with
/archives//html/Amps/2018-12/msg00023.html (9,251 bytes)

243. Re: [Amps] Input relay for QSK amp (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Sat, 8 Dec 2018 18:37:57 +0100
Bob, Years ago, I bought a lifetime supply of RJ1As for my own projects, and have tested roughly two dozen on my homebrew relay tester. The RJ1As typically close in about 2msec, with the fastest clos
/archives//html/Amps/2018-12/msg00050.html (12,714 bytes)

244. Re: [Amps] Input relay for QSK amp (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Sat, 8 Dec 2018 18:41:59 +0100
Oops, forgot the link. Sorry. Here it is; http://www.w8zr.net/QSK/qsk_QST.pdf Sent from my iPhone _______________________________________________ Amps mailing list Amps@contesting.com http://lists.co
/archives//html/Amps/2018-12/msg00052.html (8,206 bytes)

245. Re: [Amps] Input relay for QSK amp (score: 1)
Author: Jim Garland <4cx250b@miamioh.edu>
Date: Sun, 9 Dec 2018 08:22:45 -0700
Jim, You're right in principle, of course. The problem is that a well-designed amplifier relay circuit shouldn't depend on what transceiver is used. The amplifier itself should be immune to hot-switc
/archives//html/Amps/2018-12/msg00062.html (17,573 bytes)

246. Re: [Amps] Input relay for QSK amp (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Sun, 9 Dec 2018 18:06:49 +0100
False logic? I don't believe it is good design practice to ever allow an on-line high power amplifier to look into an open circuit, even if no drive is present. To do so is to invite instability. The
/archives//html/Amps/2018-12/msg00064.html (13,901 bytes)

247. Re: [Amps] Input relay for QSK amp (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Fri, 14 Dec 2018 16:23:05 -0600
Jim, I believe Paul W9IC addressed your issue, but I thought I'd weigh in, too. You're absolutely correct that there are many situations (eg, running VOX SSB with some transceivers) where the transce
/archives//html/Amps/2018-12/msg00088.html (11,231 bytes)

248. Re: [Amps] SSR in amp PS not working as expected (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Tue, 8 Jan 2019 19:17:21 -0800
Ulf, I'm currently using SSRs to control the 240VAC primaries in two large HV power supplies (one on each leg of the 240V mains) and one to switch 120VAC to my operating table. I also use one as the
/archives//html/Amps/2019-01/msg00029.html (14,361 bytes)

249. Re: [Amps] NOS Alpha 9500 (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Mon, 4 Mar 2019 22:41:05 +0100
I believe you are overthinking the precautions, Marc. Reseating the connectors probably isn't necessary, and you run the risk of damaging a connector or other component by messing with the innards. I
/archives//html/Amps/2019-03/msg00008.html (9,221 bytes)

250. Re: [Amps] Alpha 77SX forward & reverse W not working (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Sat, 30 Mar 2019 10:40:21 -0400
As I recall (and maybe I dont!),the 77SX has the same tank circuit as the 77DX, which means the plate load Z is too low for the tank components. The amp tunes to resonance, except on 10m, but not cer
/archives//html/Amps/2019-03/msg00059.html (9,210 bytes)

251. [Amps] Nylon in RF Tank Circuits (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Fri, 7 Jun 2019 18:52:37 -0400
For decades Ive avoided using nylon hardware in the vicinity of an RF tank circuit because I believed nylon was prone to absorbing RF and burning. I dont know how or when I came to learn this informa
/archives//html/Amps/2019-06/msg00022.html (6,541 bytes)

252. Re: [Amps] 4CX1000a test and gettering (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Fri, 14 Jun 2019 17:14:04 -0400
Ed, the best place to test it is in your Acom amp itself! Just run it for a few hours with filament on but offline and no RF drive. It doesnt matter if the high voltage is also on, so long as the amp
/archives//html/Amps/2019-06/msg00040.html (8,113 bytes)

253. Re: [Amps] Failure of a pair of FU728F (score: 1)
Author: Jim Garland <4cx250b@miamioh.edu>
Date: Fri, 20 Sep 2019 10:05:21 -0600
Two years ago, I completed my first tetrode amplifier (http://www.w8zr.net/160amplifier/160overview.htm), a duo-band (80m/160m) design running three Russian GU74B tetrodes. The experience taught me a
/archives//html/Amps/2019-09/msg00045.html (13,130 bytes)

254. Re: [Amps] HV Fuse (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Fri, 20 Sep 2019 16:39:42 -0700
I dont have a problem with HV fuses in parallel, Paul. Ive used two and sometimes three of the 900 MA microwave oven fuses in parallel. If there is a circuit overload, all three of the fuses will blo
/archives//html/Amps/2019-09/msg00051.html (11,882 bytes)

255. Re: [Amps] Tips For Winding a Plate Choke (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Sun, 6 Oct 2019 18:42:25 -0700
Hi Doug, There are many ways to skin a cat, but this link shows how I made the 230uH plate choke for a dual band 80/160 M amplifier. I wound the wire on a mini- lathe at a very slow speed (about 1rpm
/archives//html/Amps/2019-10/msg00023.html (11,614 bytes)

256. Re: [Amps] Tips For Winding a Plate Choke (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Mon, 7 Oct 2019 08:57:42 -0700
Oops, I meant 1rps, not 1rpm! Jim w8zr Sent from my iPhone _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
/archives//html/Amps/2019-10/msg00025.html (8,580 bytes)

257. Re: [Amps] Palstar Commander II VHF Amp Issue (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Sun, 27 Oct 2019 18:30:03 -0700
Thats a terrible idea, Dick! You could end up killing yourself or somebody else. Spend a few bucks and rewind or buy a new transformer. 73, Jim w8zr Sent from my iPhone ______________________________
/archives//html/Amps/2019-10/msg00084.html (8,236 bytes)

258. Re: [Amps] SB-220 HV Transformer Wanted ; thread stolen for bias question (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Fri, 1 Nov 2019 09:49:17 -0700
Yes! This is a clear and concise summary, Gary. The best Ive read. Thanks! 73, Jim w8zr Sent from my iPad _______________________________________________ Amps mailing list Amps@contesting.com http://
/archives//html/Amps/2019-11/msg00008.html (19,805 bytes)

259. Re: [Amps] Changing class of operation with BIAS (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Fri, 1 Nov 2019 10:52:44 -0700
Rob, I think analogies to a water pipe to describe vacuum tube conduction can be helpful in conveying very simple ideas about current and voltage, but the parallel shouldnt be pushed too far. Vacuum
/archives//html/Amps/2019-11/msg00009.html (10,095 bytes)

260. Re: [Amps] GS35B Amps Common Problem / few more comments (score: 1)
Author: MU 4CX250B <4cx250b@miamioh.edu>
Date: Tue, 5 Nov 2019 18:11:32 -0800
You may be a bit harsh, Carl! Ive lost two 8877s in the past half century or so, and it was my fault both times. The first was when I stupidly let the filament voltage drop way below specs, and the s
/archives//html/Amps/2019-11/msg00037.html (7,897 bytes)

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