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Total 306 documents matching your query.

161. Re: [Amps] 5 kw amps -- why? (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Tue, 19 Oct 2004 14:50:12 -0700
Sounds like a good reason to have a pair of 4CX2500's. Enough long RTTY CQ's and those illegal operators might find their way back down below 28.0 MHz :):) In terms of enforcement of the power limit,
/archives//html/Amps/2004-10/msg00277.html (9,572 bytes)

162. Re: [Amps] Ten-Tec Centurion (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Wed, 10 Nov 2004 22:09:22 -0800
How did you have the keying hooked up, Tom? It looks like the Centurion uses a scheme similar to the Alpha 78 whereby you plug your keyer into the amplifier to generate relay closure, and then the am
/archives//html/Amps/2004-11/msg00140.html (14,732 bytes)

163. Re: [Amps] Ten-Tec Centurion (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Fri, 12 Nov 2004 08:58:42 -0800
Tom, One interesting thing to try would be to put a shorting plug on the Centurion relay control input so that the T/R relay stays closed all the time and then check to see if any arcing occurs on le
/archives//html/Amps/2004-11/msg00175.html (13,096 bytes)

164. Re: [Amps] Here's a Shocker (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Mon, 15 Nov 2004 18:35:41 -0800
Seems to me that it is very important here to properly distinguish between the level of nervous system response (ouch factor) and the level of tissue damage or bio-function disruption (R.I.P. factor)
/archives//html/Amps/2004-11/msg00232.html (11,054 bytes)

165. Re: [Amps] Current draw at 110 volts for SB-200 and SB-1000 (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Fri, 3 Dec 2004 00:01:11 -0800
I run my Drake L-7 off a 110V drop and it seems to do fine. I get about 1200 watts output with 100 watts of drive. Checking it just now, line voltage drops from 117.7 to 111.7 VAC when I go key down
/archives//html/Amps/2004-12/msg00038.html (11,108 bytes)

166. Re: [Amps] Current draw at 110 volts for SB-200 and SB-1000 (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Fri, 3 Dec 2004 08:41:40 -0800
Steve, I was speaking of the case where I have a brick on the key (A0). When I measured the power factor of the amp in this mode a while back, it was something like 0.80. I would agree with you that
/archives//html/Amps/2004-12/msg00045.html (9,744 bytes)

167. Re: [Amps] Current draw at 110 volts for SB-200 and SB-1000 (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Fri, 3 Dec 2004 11:08:33 -0800
Okay, I see what you are getting at Steve. That makes sense, and in fact I should be able to see it if I put an oscope on the line. Perhaps I will do that sometime. BTW, FWIW when I run the L-7 off m
/archives//html/Amps/2004-12/msg00049.html (12,218 bytes)

168. Re: [Amps] 10 DB increase (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Sat, 5 Feb 2005 14:38:09 -0800
Think about the power density in the ionosphere when you spread 20 KW over a half sphere 80 or 90 KM in diameter. You are talking a sphere of surface area on the order of 8*10^9 meters^2, so power de
/archives//html/Amps/2005-02/msg00160.html (10,142 bytes)

169. Re: [Amps] 10dB and propagation (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Sun, 6 Feb 2005 18:09:15 -0800
You stole my thunder, Ian. Yuri and Rich seem to be agreeing with each other about two totally different things. What Rich was talking about is path loss that varies as a function of EIRP. In my opin
/archives//html/Amps/2005-02/msg00212.html (10,311 bytes)

170. Re: [Amps] 10dB and propagation (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Sun, 6 Feb 2005 20:59:05 -0800
would overseas Yes, and if you compare the total energy dumped into the ionosphere by ham radio operators even during a contest, it's a piddle compared to what the international broadcasters are pump
/archives//html/Amps/2005-02/msg00215.html (9,055 bytes)

171. Re: [Amps] 10dB and propagation (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Mon, 7 Feb 2005 08:50:24 -0800
hour the other, would not own FWIW, here are the HAARP antenna specifications: http://www.haarp.alaska.edu/haarp/ant4.html Maximum gain is 20dB at 3 MHz increasing to 30dB at 10 MHz. The array consis
/archives//html/Amps/2005-02/msg00224.html (10,030 bytes)

172. Re: [Amps] 10dB and propagation (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Mon, 7 Feb 2005 14:41:36 -0800
man-made That is quite correct, but it is precisely the energy in the X-ray/UV regime that effects the ionosphere, so I don't think it's so imprecise to include the energy in the upper wavelengths wh
/archives//html/Amps/2005-02/msg00260.html (11,930 bytes)

173. Re: [Amps] 10dB and propagation (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Mon, 7 Feb 2005 18:48:55 -0800
Did they publish any papers on this phenomenon? What do you mean by long - seconds, minutes, hours? And by time constant do you mean to say that at the first instant of comparison, the instantaneous
/archives//html/Amps/2005-02/msg00288.html (12,008 bytes)

174. Re: [Amps] 10dB and propagation (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Tue, 8 Feb 2005 09:56:08 -0800
So what you are saying is that at one instant with the 8171 off the signal was S-xx and then in the next instant (e.g. in the span of a few seconds) the operator turned on the 8171, and the Rx signal
/archives//html/Amps/2005-02/msg00311.html (10,597 bytes)

175. Re: [Amps] New FET's (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Thu, 10 Feb 2005 07:22:21 -0800
And to think that I was getting chewed out about discussing non-technical topics like non-linear amplifier gain, plasma heating, and ionospheric propagation. I am glad to see we have brought things b
/archives//html/Amps/2005-02/msg00404.html (8,456 bytes)

176. Re: [Amps] how to make an HF dual directional coupler? (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Thu, 3 Mar 2005 20:43:03 -0800
http://home.earthlink.net/~christrask/drctcplr.html 73 de Mike, W4EF............................................... _______________________________________________ Amps mailing list Amps@contesting.
/archives//html/Amps/2005-03/msg00038.html (7,029 bytes)

177. Re: [Amps] nylons (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Tue, 15 Mar 2005 21:02:03 -0800
I don't think you would learn much by just throwing the material into an amplifier chassis in some arbitrary fashion. The thing you want to do is induce a significant amount of displacement current i
/archives//html/Amps/2005-03/msg00359.html (9,682 bytes)

178. Re: [Amps] nylons (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Wed, 16 Mar 2005 11:41:06 -0800
I used to some to load a 3.3 GHz waveguide antenna that I worked on for the air force about 15 years ago. The machinist didn't complain and the antenna worked as expected (it was build to print). Mik
/archives//html/Amps/2005-03/msg00381.html (10,460 bytes)

179. Re: [Amps] Measuring RF Power (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Sat, 26 Mar 2005 16:40:27 -0800
Okay, David, I'll bite (I am among the 99%, I guess). Are you referring to the highest frequency component of a modulated carrier or the information bandwidth of a modulated signal? If the former, I
/archives//html/Amps/2005-03/msg00592.html (9,177 bytes)

180. [Amps] Soft Tubes? (score: 1)
Author: "Michael Tope" <W4EF@dellroy.com>
Date: Mon, 28 Mar 2005 17:25:42 -0800
Someone asked me recently if the tubes in their Alpha 78 might be going soft (they were measuring poor efficiency on 10 meters). My response was to inquire about their measurement technique in order
/archives//html/Amps/2005-03/msg00644.html (7,487 bytes)


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