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References: [ +from:W4EF@dellroy.com: 306 ]

Total 306 documents matching your query.

201. [Amps] Appraising Old Tubes (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Sat, 3 Sep 2005 14:11:55 -0700
Hi All, I have some old tubes (Eimac 250TH's, 250T, CWL-803, CWL-861, etc) that I have accumulated over the years from various estates that I have helped to liquidate. I will probably never use them
/archives//html/Amps/2005-09/msg00025.html (6,966 bytes)

202. Re: [Amps] Suggestions for new Alpha Owner? (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Tue, 27 Sep 2005 07:04:52 -0700
http://www.dellroy.com/W4EF's-Ham-Radio-Page/Alpha78/Alpha78.htm 73 de Mike, W4EF........................ _______________________________________________ Amps mailing list Amps@contesting.com http://
/archives//html/Amps/2005-09/msg00330.html (7,245 bytes)

203. Re: [Amps] Suggestions for new Alpha Owner? (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Tue, 27 Sep 2005 15:33:55 -0700
I strongly agree, John. I measured the choke impedance of the Alpha 78 with the choke installed in the amplifier and it definitely has a series resonance around 25 MHz. Load up on 12 meters at your o
/archives//html/Amps/2005-09/msg00338.html (8,784 bytes)

204. Re: [Amps] Antenna Tuner Overheating (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Sat, 15 Oct 2005 19:57:44 -0700
The Ten-Tec 4229 which I believe is similar to the Tuners Jim describes uses ceramic disc high voltage capacitors to pad the air variable capacitor. I don't use my 4229 anymore (I need to clean the r
/archives//html/Amps/2005-10/msg00421.html (8,340 bytes)

205. Re: [Amps] schematic software? (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Tue, 1 Nov 2005 20:29:05 -0800
Ditto! Been using it at work and at home for schematics for some time. Just started using the PWB layout last week. Almost done with my first board. Great program. Mike, W4EF................ ________
/archives//html/Amps/2005-11/msg00022.html (7,633 bytes)

206. Re: [Amps] Alpha 78 on 17 Meters (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Wed, 7 Dec 2005 08:06:18 -0800
Frank, The tuning is pretty sharp for 17 meters. In fact, the first time I tried it, I concluded that it wouldn't work on 17 meters at all. The club I belong to has 2 Alpha 78's. Recently I had one o
/archives//html/Amps/2005-12/msg00064.html (8,330 bytes)

207. Re: [RFI] [Amps] new mobile amps from THP (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Wed, 11 Jan 2006 07:22:01 -0800
Jim, The transmission in my 2001 Ford Ranger "crashes" occasionally even without RF stimulus. Fortunately, you can reboot the transmission by turning off the ignition and restarting the engine. Makes
/archives//html/Amps/2006-01/msg00339.html (8,902 bytes)

208. Re: [Amps] "I gotta tell this" (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Thu, 30 Mar 2006 05:17:50 -0800
Experience suggests that the MCTQ (mean calls to QSO) curve in a big pileup isn't necessarily a linear function of power. In a big pileup you could end up calling all day at 100 watts, in which case
/archives//html/Amps/2006-03/msg00774.html (9,884 bytes)

209. Re: [Amps] Step Start And Transformer Surge Current (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Tue, 30 May 2006 17:36:53 -0700
Will, et al: Here is McLyman's website: http://www.kgmagnetics.com/ Looks like lots of good information on magnetics design. 73, Mike W4EF............................................. _______________
/archives//html/Amps/2006-05/msg00532.html (7,113 bytes)

210. Re: [Amps] New Dummy Load (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Fri, 16 Jun 2006 11:11:57 -0700
Yes, it looks like it will shunt $2000 continuous to ground :):) Mike, W4EF............................ _______________________________________________ Amps mailing list Amps@contesting.com http://li
/archives//html/Amps/2006-06/msg00307.html (7,884 bytes)

211. Re: [Amps] IM distortion and such (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Mon, 26 Jun 2006 15:44:38 -0700
Will, Since when do you need a PE license to be an electronic design engineer? Only a handful of the design engineers that I have worked with over the years actually had a PE license. 73, Mike W4EF..
/archives//html/Amps/2006-06/msg00471.html (11,836 bytes)

212. Re: [Amps] IM distortion and such (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Mon, 26 Jun 2006 20:02:43 -0700
Pulsed measurements. BTW, if you do the math -> 4000 volts x 400mA = 1600 watts input power. At 70% efficiency, that's ~500 watts plate dissipation, so there's some consistency between the numbers. I
/archives//html/Amps/2006-06/msg00487.html (9,836 bytes)

213. Re: [Amps] IM distortion and such (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Wed, 28 Jun 2006 07:20:09 -0700
Yes, definitely, Peter. I recall an IEEE talk on Gallium Nitride amplifier technology that I attended about 6 months ago where the presenter showed several IMD curves for class B amplifiers that had
/archives//html/Amps/2006-06/msg00562.html (9,629 bytes)

214. Re: [Amps] IM distortion and such (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Thu, 29 Jun 2006 07:12:10 -0700
I was looking at this earlier this evening. The load line is just a straight line approximation based on a couple of points. The actual transfer curve (Eb vs Eg) will depend on the slope and spacing
/archives//html/Amps/2006-06/msg00628.html (11,622 bytes)

215. Re: [Amps] IM distortion and such (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Thu, 29 Jun 2006 21:06:36 -0700
Yes, I agree, Gary. 73, Mike W4EF...................... _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
/archives//html/Amps/2006-06/msg00650.html (10,295 bytes)

216. Re: [Amps] Mains Isolation Transformer (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Sat, 1 Jul 2006 11:08:44 -0700
The current balun on your feedline should help keep the RF noise from the AC mains from getting coupled into your antenna. K9YC has reported that several of his fellow hams in the Chicago area have h
/archives//html/Amps/2006-07/msg00020.html (8,453 bytes)

217. Re: [Amps] Again (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Sun, 2 Jul 2006 05:27:14 -0700
Hi Mike, In principle for a given operating class (A, AB1, AB2, C), matching the load impedance presented by the tank circuit to the output impedance of the tube provides maximum available output pow
/archives//html/Amps/2006-07/msg00044.html (8,795 bytes)

218. Re: [Amps] Maximum RF output in practical application: 4-250A (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Sun, 2 Jul 2006 07:03:04 -0700
There is an intersting article in QEX this month where the author describes a 2KW PEP 80/40 meter output amplifier using 4 TV sweeps tubes with a switchmode power supply providing envelope restoratio
/archives//html/Amps/2006-07/msg00048.html (9,324 bytes)

219. Re: [Amps] Maximum RF output in practical application: 4-250A (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Mon, 3 Jul 2006 08:45:26 -0700
The market could take of the enforcement, Joe. Add the spectral mask to the part 97, and then overlay the mask on the ARRL product test report IMD plots. You can bet your bottom dollar that this woul
/archives//html/Amps/2006-07/msg00104.html (10,120 bytes)

220. Re: [Amps] Maximum RF output in practical application: 4-250A (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Mon, 3 Jul 2006 10:29:56 -0700
Okay, so how is that tested? White noise? Tones? Voice? Max power? Max allowed ALC? No ALC? Come on Michael, there's no way that would be anything but arbitrary, as a lot of the ARRL's "measurements"
/archives//html/Amps/2006-07/msg00117.html (10,876 bytes)

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