Mail Archive Search: <+from:jim@audiosystemsgroup.com>

Results:

References: [ +from:jim@audiosystemsgroup.com: 728 ]

Total 728 documents matching your query.

101. Re: [Amps] TenTec Titan 425 HV filter caps (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Thu, 11 Oct 2007 08:39:31 -0700; The original parts in my Titans are Mallory CGS401T450R5L (400 uF, 450VDC, 85 deg C). The best price I found was from Allied Electronics. Don't remember what I paid. They aren't cheap, and they weren; /archives//html/Amps/2007-10/msg00132.html (7,096 bytes)
102. Re: [Amps] Fans (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Mon, 22 Oct 2007 21:13:29 -0700; If it's bad on the lower bands, there's a good chance that it is the result of noise current flowing through a large loop area. Figure out a way to reduce that loop area and you'll kill the noise. Al; /archives//html/Amps/2007-10/msg00237.html (6,888 bytes)
103. [Amps] Ten Tec Titan Filter Caps (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Wed, 07 Nov 2007 19:35:44 -0800; A month or so ago, someone was asking about a source for these, and the price. I bought some a year ago, and looked pretty good for the best deal, which turned out to be Allied. Mouser was second bes; /archives//html/Amps/2007-11/msg00109.html (6,860 bytes)
104. Re: [Amps] Tom W8JI (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Sat, 10 Nov 2007 07:32:01 -0800; Count me among those who very much values Tom's contributions to any discussion. I wish him a speedy recovery, and hope he'll return to this and other lists once he's back up to fighting weight. 73,; /archives//html/Amps/2007-11/msg00130.html (7,213 bytes)
105. Re: [Amps] Alpha 78 problem (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Sat, 10 Nov 2007 07:54:06 -0800; I don't know that amp, but it may be a vacuum relay made by Jennings or Kilovac. Check the schematic/parts list. A company called Gigavac makes replacements for both, and sells them to hams at a nice; /archives//html/Amps/2007-11/msg00132.html (7,640 bytes)
106. Re: [Amps] 50 Ohm Loads (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Sun, 11 Nov 2007 23:24:02 -0800; At a single frequency (or depending on the Q, a relatively narrow range). The laws of physics, as described by the classic resonant frequency curves, apply in full. Wire wound resistors as an RF dumm; /archives//html/Amps/2007-11/msg00158.html (7,572 bytes)
107. Re: [Amps] 50 Ohm Loads (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Mon, 12 Nov 2007 08:48:50 -0800; It sure is a narrow range -- +/- 20 kHz! The laws of physics have not changed in my lifetime. 73, Jim _______________________________________________ Amps mailing list Amps@contesting.com http://list; /archives//html/Amps/2007-11/msg00163.html (7,689 bytes)
108. Re: [Amps] 50 Ohm Loads (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Mon, 12 Nov 2007 09:35:01 -0800; I know you said that, but I don't believe it. 540-1700 kHz is a 3:1 range. In most RF systems, a dummy load needs to be pretty close to purely resistive. It is hard to believe that what you describe; /archives//html/Amps/2007-11/msg00167.html (8,355 bytes)
109. Re: [Amps] 50 Ohm Loads (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Mon, 12 Nov 2007 11:26:01 -0800; Yep. And the most practical way to do that is to measure it at RF. The test setup I published in my RFI tutorial to measure chokes would work. Most antenna analyzers would at least get us in the ball; /archives//html/Amps/2007-11/msg00174.html (8,156 bytes)
110. Re: [Amps] 50 Ohm Loads (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Mon, 12 Nov 2007 15:21:32 -0800; How did you measure those values? At what frequency? What was the resistance at the frequency of the measurement? These are important questions, because that coil that we're calling a resistor has L,; /archives//html/Amps/2007-11/msg00182.html (8,283 bytes)
111. Re: [Amps] 50 Ohm Loads (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Tue, 13 Nov 2007 08:28:44 -0800; Don't know who Caddock is. First, we're talking about wire wound resistors here, not general coils. Second, if you believe a technique like this will work, I suggest you build one and measure it. 73,; /archives//html/Amps/2007-11/msg00187.html (8,351 bytes)
112. [Amps] Grid Protection Circuit for Titan 425 (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Mon, 19 Nov 2007 14:53:07 -0800; Several months ago, Tom Rauch observed that a protection circuit mod for the older vintage amps like this one that use 3CX800A7 tubes would be a very good idea, since a primary failure mode is exceed; /archives//html/Amps/2007-11/msg00278.html (7,827 bytes)
113. Re: [Amps] Grid Protection Circuit for Titan 425 (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Tue, 20 Nov 2007 08:10:01 -0800; As I read the doc for it, Ian's board offers protection for several faults. But the one I am most concerned with is overdriving the grids, which is a well known failure mechanism on 3CX800A7 tubes. T; /archives//html/Amps/2007-11/msg00284.html (7,970 bytes)
114. Re: [Amps] 220V wiring logistics (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Mon, 03 Dec 2007 11:26:25 -0800; While there may be CODE issues, it is pretty SAFE to install a new, proper 240V outlet wired with the hot wire from the "A" side of the panel going to one hot blade of the outlet and the hot wire fro; /archives//html/Amps/2007-12/msg00010.html (8,097 bytes)
115. Re: [Amps] Autotransformer (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Fri, 07 Dec 2007 08:56:39 -0800; Yes, it would need to handle that power. BUT: Do a little research/study on the topic of "boost/buck" transformers. A boost/buck transformer is a small transformer with a step-down ratio whose second; /archives//html/Amps/2007-12/msg00031.html (7,765 bytes)
116. Re: [Amps] MFJ and Dahl (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Sun, 09 Dec 2007 11:48:27 -0800; I strongly disagree. When a company blankets a market with low cost low quality stuff (as MFJ and Walmart do), it usually pushes other companies with better quality stuff at a somewhat higher prices; /archives//html/Amps/2007-12/msg00109.html (8,259 bytes)
117. Re: [Amps] input/output transformer switching (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Thu, 13 Dec 2007 09:59:47 -0800; type I've missed the original question in this thread, BUT, perhaps I can cast some light on the topic. in transformers. So is #67. #43 is a HIGH loss material at VHF, and is generally NOT suitable f; /archives//html/Amps/2007-12/msg00155.html (8,239 bytes)
118. Re: [Amps] Alpha 87A Tubes 3CX800A7 and the 3CX P 800A7 (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Mon, 31 Dec 2007 10:18:59 -0800; Excessive grid current is the major failure mode of 3CX800A7 tubes. 60 mA per tube is the absolute maximum. I religiously tune my Titan 425's (two 3CX800A7's) so that the grid current for two tubes c; /archives//html/Amps/2007-12/msg00290.html (8,295 bytes)
119. Re: [Amps] tuning bandpass filters (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Mon, 21 Jan 2008 09:39:16 -0800; It's critical to understand that a filter is a passive network that interacts with the impedance of the source and the impedance of the load. When we design filters, we make the optimistic assumption; /archives//html/Amps/2008-01/msg00131.html (8,268 bytes)
120. [Amps] Ten Tec Titan Partial Schematic (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Thu, 24 Jan 2008 16:14:26 -0800; I now own three of these vintage amps, and they require frequent maintenance to keep them running. Ten Tec's printed schematics are spread across a dozen sheets, and are difficult to follow. This par; /archives//html/Amps/2008-01/msg00165.html (7,353 bytes)

Current List: 101 - 120
Page: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20]