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181. Re: [Amps] High SWR, (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 23 Apr 2009 10:05:59 -0700
The author of this false statement would be far better off learning how transmission lines work by studying the ARRL Handbook and ARRL Antenna Book than the manual for someone's SWR bridge. The conc
/archives//html/Amps/2009-04/msg00270.html (9,236 bytes)

182. Re: [Amps] High SWR (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 23 Apr 2009 11:33:40 -0700
Few broadcast systems are "single frequency." They may have a single carrier, but most are concerned with good phase response over some finite bandwidth depending on what modulation scheme is employe
/archives//html/Amps/2009-04/msg00282.html (9,571 bytes)

183. Re: [Amps] High SWR (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 23 Apr 2009 16:31:06 -0700
worry items Maybe that was true where you lived, but not where I lived (in WV). SWR bridges were a popular accessory when I was in high school (1956-59). Most hams I knew used resonant antennas if th
/archives//html/Amps/2009-04/msg00297.html (9,760 bytes)

184. Re: [Amps] High SWR (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sat, 25 Apr 2009 10:17:04 -0700
There are chapters in one of my tutorials that attempt to shed some light the subject of common mode chokes, often called "current baluns." http://audiosystemsgroup.com/RFI-Ham.pdf 73, Jim Brown K9YC
/archives//html/Amps/2009-04/msg00345.html (9,188 bytes)

185. Re: [Amps] Sleeve Baluns FS (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sat, 25 Apr 2009 11:55:28 -0700
You didn't say what ferrite material these are, but this is pretty close to what Palomar sells as a "high power current balun." That one is a VERY inferior version of W2DU's choke. 5 cores of any mat
/archives//html/Amps/2009-04/msg00350.html (7,333 bytes)

186. Re: [Amps] Sleeve Baluns FS (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sat, 25 Apr 2009 22:57:41 -0700
No, I didn't miss that at all, Vic. I have cores like that (including some that I bought from Palomar to see what they were selling as a balun). My comments are based on those cores. It is a very poo
/archives//html/Amps/2009-04/msg00365.html (7,573 bytes)

187. Re: [Amps] Sleeve Baluns FS (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sun, 26 Apr 2009 10:18:23 -0700
It depends entirely on your definition of "a pretty decent choke." My MINIMUM definition of an ACCEPTABLE choke are the original W2DU chokes, as published on his website. Google to find it. The versi
/archives//html/Amps/2009-04/msg00368.html (8,752 bytes)

188. Re: [Amps] DEAD Alpha 91B (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 18 May 2009 09:03:33 -0700
Mike, While you're in there, you might want to check to see if this model is running a 120V fan between one side of 240V and ground. As you know, that's a no-no, and generates problems with magnetic
/archives//html/Amps/2009-05/msg00106.html (7,669 bytes)

189. Re: [Amps] HV switch-mode power supply (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Fri, 22 May 2009 18:11:20 -0700
You couldn't say that if you lived in California! :) I rarely get a monthly bill that doesn't have some kWh at the 2X penalty rate, and you can hit the 3X penalty in a summer month with a couple of c
/archives//html/Amps/2009-05/msg00159.html (7,366 bytes)

190. Re: [Amps] HV switch-mode power supply (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Fri, 22 May 2009 20:28:40 -0700
Near San Francisco, my residential base rate is $0.115/kWh for 350 kWh per month during the summer. For the next 100 kWh per month, it jumps to $0.13, then to $0.23/kWh for 200 kWh, then to $0.325 fo
/archives//html/Amps/2009-05/msg00163.html (8,326 bytes)

191. Re: [Amps] Titan quits query (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 24 Jun 2009 15:07:05 -0700
Two fuses on the power supply. They will occasionally blow, with the symptoms noted. I use standard 3AG or 3AB 15A fast blow fuses. They blow in pairs. I believe the manual calls for 20A, but when so
/archives//html/Amps/2009-06/msg00110.html (7,457 bytes)

192. Re: [Amps] toroidal transformers (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 25 Jun 2009 13:03:36 -0700
And hopefully less leakage flux? 73, Jim K9YC _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
/archives//html/Amps/2009-06/msg00119.html (6,919 bytes)

193. Re: [Amps] Titan quits query more (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sun, 28 Jun 2009 14:00:01 -0700
, There is a 90% schematic, with notes, on my website. It might give you some troubleshooting ideas. The 10% that's left out is the RF input and output circuitry and switching. The power supply stuff
/archives//html/Amps/2009-06/msg00134.html (8,570 bytes)

194. Re: [Amps] 240V Outlet (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sun, 09 Aug 2009 09:31:27 -0700
It depends on how the power supply is wired. One good way to get 120 volts from a 240 volt circuit is by running that load (typically a cooling fan) from half of a center-tapped primary of the main p
/archives//html/Amps/2009-08/msg00148.html (8,452 bytes)

195. Re: [Amps] 240V Outlet (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sun, 09 Aug 2009 21:49:15 -0700
Yes, if the ground is also #12 or larger. You can (and should) also change the outlets. Jim K9YC _______________________________________________ Amps mailing list Amps@contesting.com http://lists.con
/archives//html/Amps/2009-08/msg00193.html (8,254 bytes)

196. Re: [Amps] 240V Outlet (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sun, 09 Aug 2009 21:58:26 -0700
YES. The NEC is quite clear on this. It's a safety issue. There is a very good reason for pulling bigger wire if the circuit will be heavily loaded, and it isn't heat, it's regulation. Nearly all ele
/archives//html/Amps/2009-08/msg00194.html (9,086 bytes)

197. Re: [Amps] 240V Outlet (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sun, 09 Aug 2009 22:05:14 -0700
So far, that doesn't seem like it would take much to fix it. Simply put a modern 120V 3-wire cord on the 120V supply and plug it into a legal 120V outlet. If it was me, I would put that outlet in the
/archives//html/Amps/2009-08/msg00196.html (9,481 bytes)

198. Re: [Amps] 240V Outlet (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 10 Aug 2009 09:51:03 -0700
In a properly wired circuit, current from the hot (phase) conductor returns on the neutral, so all of the associated magnetic field is contained entirely in the region between and immediately around
/archives//html/Amps/2009-08/msg00232.html (9,049 bytes)

199. Re: [Amps] 240V Outlet (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 11 Aug 2009 00:27:48 -0700
On Sun, 9 Aug 2009 22:59:50 -0700 (PDT), jimsmitheguard-a@yahoo.com wrote: You have a rather limited view of a world that far more varied than you imagine. I work in the world of pro audio, and there
/archives//html/Amps/2009-08/msg00262.html (9,903 bytes)

200. Re: [Amps] 240V Outlet (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 11 Aug 2009 13:31:03 -0700
NO. NO! NO! The advice quoted below is NOT mine. My post took strong exception to the advice quoted below. You have a rather limited view of a world that far more varied than you imagine. I work in t
/archives//html/Amps/2009-08/msg00268.html (9,176 bytes)


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