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References: [ +from:jim@audiosystemsgroup.com: 1945 ]

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261. Re: [RFI] TV RFI - an update 2 (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 14 Feb 2008 21:01:34 -0800
There is MEASURED data on my website for 1-14 turn chokes wound with #18 wire on 2.4" toroids in #31, #43, #61, #77, and #78. There is also MEASURED data for coaxial chokes on #31 cores. http://audio
/archives//html/RFI/2008-02/msg00036.html (7,285 bytes)

262. Re: [RFI] 2 Wire 2701 HG (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sat, 23 Feb 2008 13:51:57 -0800
As long as the electronics wants 5VDC to run, it doesn't much matter whether that 5V comes from the el cheapo noise generator or a much better one. You could, for example, simply use a 6V filament tr
/archives//html/RFI/2008-02/msg00050.html (7,418 bytes)

263. Re: [RFI] impulsive RFI (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 03 Mar 2008 10:30:15 -0800
Jim's point about directional properties of antennas away from their design frequencies is well taken. Another hint, learned from Fox Hunting, is that an HT with a duck can be form a directional ante
/archives//html/RFI/2008-03/msg00007.html (6,999 bytes)

264. Re: [RFI] Modem PS noise (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 05 Mar 2008 09:42:49 -0800
And I'll emphasize two VERY important phrases in Dale's preceding sentence, that he clearly understands but didn't articulate in detail -- "in the correct places" and "good board layout techniques."
/archives//html/RFI/2008-03/msg00012.html (7,863 bytes)

265. Re: [RFI] Digital TV Problems (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 31 Mar 2008 17:56:23 -0700
A connection to EARTH is important for lightning protection. A connection to EARTH is NOT part of a solution to interference problems. http://audiosystemsgroup.com/RFI-Ham.pdf 73, Jim Brown K9YC ____
/archives//html/RFI/2008-03/msg00017.html (6,777 bytes)

266. Re: [RFI] Digital TV Problems (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 02 Apr 2008 20:12:37 -0700
On Wed, 2 Apr 2008 19:27:50 -0700 (GMT-07:00), Cortland Richmond wrote: with This is ALWAYS UNSAFE unless some other robust connection from that equipment to the power system ground replaces it. We'v
/archives//html/RFI/2008-04/msg00003.html (8,009 bytes)

267. Re: [RFI] AC Line filters (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 03 Apr 2008 10:06:54 -0700
You can, indeed, roll your own, following guidelines in my RFI tutorial. You can also buy pretty good line filters from a surplus house called Halted Specialties (also known as HSC). On the link belo
/archives//html/RFI/2008-04/msg00010.html (8,889 bytes)

268. Re: [RFI] Digital TV Problems (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 03 Apr 2008 17:19:12 -0700
That has the potential to be a good move. The existing coax may not be the greatest, and there may be less than wonderful connectors. The two combined might reduce leakage by enough to get the interf
/archives//html/RFI/2008-04/msg00014.html (8,085 bytes)

269. Re: [RFI] AC Line filters- Direct-Drive Washers (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Fri, 04 Apr 2008 09:40:50 -0700
YES! YES! YES! These words deserve to be shoved you know where. Returning the defective product is the only way I can think of to do that. If it is, indeed, common mode on the power cord, that's pret
/archives//html/RFI/2008-04/msg00021.html (9,842 bytes)

270. Re: [RFI] AC Line filters- Direct-Drive Washers (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Fri, 04 Apr 2008 14:43:43 -0700
Dale, WA9ENA, has given you some great advice. Larry, W0QE, made an excellent observation about this in a conversation we had offline. If the interfering signal is 50dB over S9, you've got to do a MA
/archives//html/RFI/2008-04/msg00025.html (10,280 bytes)

271. [RFI] Collected Writings of Larson E. Rapp Published (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Fri, 04 Apr 2008 16:36:25 -0700
This was in the ARRL Letter today. It gives me great pleasure to see that the contributions over nearly three decades of this giant of an engineer have finally been recognized. We do, indeed, stand o
/archives//html/RFI/2008-04/msg00026.html (7,900 bytes)

272. Re: [RFI] TV Converter Boxes & RFI (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sat, 19 Apr 2008 15:52:49 -0700
There are two VERY different issues being addressed here. First, you should define what a "Bright House" cable is so that we understand YOUR question. Is it coax, or is it some other kind of cable? W
/archives//html/RFI/2008-04/msg00029.html (12,078 bytes)

273. Re: [RFI] TV Converter Boxes & RFI (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sat, 19 Apr 2008 18:49:28 -0700
Someone who knows more about some of the newer CATV standards may have meaningful input on this. As long as it's a good clean install of quality coax, and all the terminations are clean so that there
/archives//html/RFI/2008-04/msg00031.html (7,626 bytes)

274. Re: [RFI] Microwave RFI - radiated (?) (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 07 May 2008 16:31:30 -0700
Try more toroids in the stack and use close-wound turns to lower the resonant frequency, using the data for coax of similar size as a guide. If that helps, it's being radiated by the power cord, If i
/archives//html/RFI/2008-05/msg00004.html (7,023 bytes)

275. Re: [RFI] rfi from Refrigerator (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 23 Jun 2008 08:31:58 -0700
Hello Kostas, Several thoughts. First, if you have owned the refrigerator for years or months and the noise just began, it may be the result of some failure within the refrigerator. If that is true,
/archives//html/RFI/2008-06/msg00006.html (8,647 bytes)

276. Re: [RFI] rfi from Refrigerator (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 23 Jun 2008 21:54:42 -0700
The way to break that down is to tell him that 1) You view the noise as simply a symptom of some failure in the refrigerator, and that hopefully it will give him a clue about how to find the problem
/archives//html/RFI/2008-06/msg00008.html (7,639 bytes)

277. Re: [RFI] 6M Getting into TV Channel 3 - CLARIFIED! (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 03 Jul 2008 09:50:25 -0700
I'd say common mode and differential mode are equally likely. A ferrite choke on the coax is the right fix for common mode. A bandpass filter (or bandstop filter) is the right fix for differential mo
/archives//html/RFI/2008-07/msg00007.html (8,352 bytes)

278. Re: [RFI] RFI in home security system (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sun, 06 Jul 2008 16:00:55 -0700
Hang on a minute -- that telephone line is an ANTENNA! OF COURSE it can be part of the problem, but not because there's something WRONG with it, only because it's acting as an antenna! Let's get our
/archives//html/RFI/2008-07/msg00013.html (8,295 bytes)

279. Re: [RFI] [Amps] So-Called Utility "Smart Meters" (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 12 Aug 2008 10:03:53 -0700
I suggest that you do what I have done for at least 15 years for both my power and heating fuel -- generate a spreadsheet with the information that comes on your monthly bill and study the trends. Yo
/archives//html/RFI/2008-08/msg00004.html (8,976 bytes)

280. Re: [RFI] So-Called Utility "Smart Meters" (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 12 Aug 2008 18:59:11 -0700
These guys should probably stick to bending pipe. While the bill may go up, it will likely be the result of how the meter responds to things like current waveform and power factor, and what the tarif
/archives//html/RFI/2008-08/msg00014.html (8,644 bytes)

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