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References: [ +from:jim@audiosystemsgroup.com: 1809 ]

Total 1809 documents matching your query.

141. Re: [RFI] RF Quiet Laptop for Mobile Console? (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 22 May 2006 07:51:40 -0700
Most ham gear is shielded, and radiates little RF trash. It's the antennas that have the potential for problems. My IBM T22 and T41 work quite nicely from a Targus 12v universal power supply that I b
/archives//html/RFI/2006-05/msg00033.html (10,402 bytes)

142. Re: [RFI] Power line Noise (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 07 Jun 2006 14:02:06 -0700
How does this relate to what I've heard about arcing at insulators due to humidity or corona discharge varying with weather conditions (which in some parts of the world vary with the time of day)? Ji
/archives//html/RFI/2006-06/msg00009.html (7,199 bytes)

143. Re: [RFI] Power line Noise (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 08 Jun 2006 16:28:44 -0700
Yes, but I suspect that propagation is USUALLY less of an issue because the sources are usually too close to the victim to be affected by weather-related changes in propagation. That is, weather-rela
/archives//html/RFI/2006-06/msg00021.html (8,876 bytes)

144. [RFI] Technical Paper on Ferrites (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 15 Jun 2006 13:03:21 -0700
The paper I presented at the NY AES last fall is now on my website for free download. http://audiosystemsgroup.com/AESPaperFerritesASGWeb.pdf Jim Brown K9YC __________________________________________
/archives//html/RFI/2006-06/msg00027.html (6,444 bytes)

145. Re: [RFI] second floor grounding (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sun, 30 Jul 2006 13:29:09 -0700
There are several tutorials on my website that should help you understand the issues. http://audiosystemsgroup.com/publish Start with a careful study the "Power and Grounding" tutorial as background.
/archives//html/RFI/2006-07/msg00025.html (7,165 bytes)

146. Re: [RFI] Ambient Noise Levels (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 08 Aug 2006 22:45:48 -0700
I agree with Tom -- it's noise from far away, propagated just like any other RF signal. When 6M is open, for example, I hear birdies that I don't hear when it isn't. And during a major blackout not l
/archives//html/RFI/2006-08/msg00006.html (7,094 bytes)

147. Re: [RFI] Ambient Noise Levels (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 09 Aug 2006 21:15:53 -0700
Yes, and this is exactly what W8JI is saying too. When noise is generated, it can cause current to flow in a wire, and that wire will act as an antenna, just like any other wire carrying RF current.
/archives//html/RFI/2006-08/msg00009.html (9,114 bytes)

148. Re: [RFI] [BULK] Re: Ambient Noise Levels (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 09 Aug 2006 22:18:57 -0700
Of course the noise at any location will be the sum of noise from many sources, some of them local, some of them distant. A few of those that are local may be close enough to be in their near field.
/archives//html/RFI/2006-08/msg00012.html (8,352 bytes)

149. Re: [RFI] [BULK] Re: Ambient Noise Levels (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 10 Aug 2006 08:51:13 -0700
One excellent source is "Noise Reduction Techniques in Electronic Systems" by Henry Ott. The 2nd edition was published in 1988, and is in print. You can order it from any standard source, and also fr
/archives//html/RFI/2006-08/msg00017.html (9,627 bytes)

150. Re: [RFI] [BULK] Re: Ambient Noise Levels (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 10 Aug 2006 12:30:30 -0700
NO! I didn't say that. I quoted someone (who signed "JimP") who said something I disagreed with and said that I disagreed! And then someone quoted some of my post in a way that attributed it to me, I
/archives//html/RFI/2006-08/msg00023.html (6,877 bytes)

151. Re: [RFI] 138kv power lines (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 15 Aug 2006 17:12:05 -0700
N9GL, a real EMC consultant and EE based near Chicago, is a consultant to both ARRL and the FCC on the health aspects of EMI exposure. See the following for some of his work. http://www.arrl.org/rfsa
/archives//html/RFI/2006-08/msg00060.html (7,318 bytes)

152. Re: [RFI] Toyota Special Instructions (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 23 Aug 2006 12:54:17 -0700
Same sort of admonition in the manual for my 2006 Toyota Sequoia (big SUV). No issues on VHF/UHF with 100 watts, but train wreck on HF -- 100 watts on 20 meters crashed the car's computer. No damage,
/archives//html/RFI/2006-08/msg00072.html (8,697 bytes)

153. Re: [RFI] Honda Generator RFI? (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sat, 16 Sep 2006 16:50:31 -0700
because NEC. Those electricians may be trying to apply residential standards to outdoor portable systems, and they may not apply. Someone more familar with NEC can probably enlighten us further. Note
/archives//html/RFI/2006-09/msg00006.html (9,369 bytes)

154. Re: [RFI] Honda Generator RFI? (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sat, 16 Sep 2006 22:27:20 -0700
So it sounds like some blame can be assigned to the radio or the radio's DC power supply having lousy filtering on its power leads! Jim K9YC _______________________________________________ RFI mailin
/archives//html/RFI/2006-09/msg00011.html (7,509 bytes)

155. Re: [RFI] Winding RG-6 around a toroid (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 19 Sep 2006 23:06:41 -0700
I agree. Some foam dielectrics are more fragile than others, and some center conductors are more inflexible than others. Combine the two and you could poke a short into the cable. Also suspect that y
/archives//html/RFI/2006-09/msg00028.html (7,081 bytes)

156. Re: [RFI] LCD Monitors (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sun, 24 Sep 2006 09:10:34 -0700
That's hard, because sources of the hardware tend to change at the whim of the bean counters and/or purchasing agent. As others have noted, LCD's are generally quiet, with power supplies being the po
/archives//html/RFI/2006-09/msg00039.html (7,646 bytes)

157. Re: [RFI] RFI all over the band (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 02 Oct 2006 11:10:42 -0700
I agree with others that this is a very useful tool in chasing down RFI. Consider this basic principle. For low frequencies, the entire length of a long power line will be the radiator, so direction
/archives//html/RFI/2006-10/msg00007.html (8,416 bytes)

158. [RFI] Behringer RFI (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 19 Oct 2006 10:06:38 -0700
The FCC has issued a "Notice of Apparent Liability for Forfeiture and Order" against Behringer USA, including a $1,000,000 fine. The offense is the importation and sale of "50 models of unauthorized
/archives//html/RFI/2006-10/msg00028.html (7,148 bytes)

159. Re: [TowerTalk] Behringer RFI (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 19 Oct 2006 20:24:49 -0700
Behringer is NOT in any way high quality, but it is low cost. Mackie and Aphex are two companies who took successful legal action against Behringer, but they are FAR from the only companies whose pro
/archives//html/RFI/2006-10/msg00037.html (8,092 bytes)

160. Re: [RFI] Intermod/Rectification (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 24 Oct 2006 09:25:48 -0700
Consider the possibility (even the liklihood) that the problem is not in your system, and may even be miles away! All of the things that could cause detection in your antenna could do the same at the
/archives//html/RFI/2006-10/msg00042.html (8,038 bytes)


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