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Total 1814 documents matching your query.

21. Re: [RFI] Re: RFI to intercom (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 23 Aug 2004 12:09:25 -0500
identifies M&S Music on the Model sticker at my house (which has no RFI problem) and an identical unit at my neighbors, who can hear me on all 6 speakers, when I operate on 12 and 10 meters, I have t
/archives//html/RFI/2004-08/msg00053.html (8,602 bytes)

22. Re: [RFI] Recent Posting on RFI with intercom. (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 23 Aug 2004 14:07:07 -0500
a FM That's because it isn't the FM radio that is causing the problem, but rather that the RF current flowing on the shield of the FM antenna is getting into the intercom's electronics. In other word
/archives//html/RFI/2004-08/msg00057.html (9,418 bytes)

23. Re: [RFI] Earth isolation (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 08 Sep 2004 14:24:58 -0500
MDS? Is there some particular problem you are having? Tom Rauch has observed, and I generally agree, that most "RF in the shack" problems are really antenna problems. I would extend that statement to
/archives//html/RFI/2004-09/msg00044.html (9,491 bytes)

24. Re: [RFI] Earth isolation (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 08 Sep 2004 22:44:18 -0500
What you really did was reduce the current flowing in those unintential antennas by adding impedance to the return path. That was a band-aid made necessary by the pin 1 problems in the gear. The more
/archives//html/RFI/2004-09/msg00048.html (8,267 bytes)

25. Re: [RFI] Earth isolation (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 08 Sep 2004 23:12:41 -0500
That is not the model I am thinking of. Rather, it is of a cable acting as a short long-wire antenna, and there is a current path for it, just as with any antenna. The current path for many ( most) l
/archives//html/RFI/2004-09/msg00049.html (9,761 bytes)

26. Re: [RFI] Earth isolation (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 09 Sep 2004 07:50:06 -0500
No. You have several misunderstandings here. 1. The so-called pin 1 problem is a mis-wiring of a SHIELD connnection. 2. It is NOT associated with intentional antennas -- that is, the antennas we norm
/archives//html/RFI/2004-09/msg00054.html (11,595 bytes)

27. RE: [RFI] Earth isolation (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 09 Sep 2004 09:10:06 -0500
Leave out the word "characteristic" -- it's not a transmission line. Just plain old series impedance. Now the sentence is right on! Yes Again, not the right words, but the right problem. The single p
/archives//html/RFI/2004-09/msg00058.html (7,745 bytes)

28. Re: [RFI] BBC Concerns over BPL Interference to SW Broadcasting (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 14 Sep 2004 12:11:34 -0500
The DRM folks (Digital Radio Mondiale) organized a fine workshop at the spring international meeting of the AES (Audio Engineering Society) this spring. I attended the workshop and asked the broadcas
/archives//html/RFI/2004-09/msg00079.html (7,835 bytes)

29. Re: [RFI] DirecTV TVI Issue (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 21 Sep 2004 17:57:23 -0500
I would put my first money on 1) common mode on the RG-6 2) the TV set and connections to it 3) Pin 1 problems in a home theater setup Both could probably be fixed with the RIGHT ferrite choke. Consi
/archives//html/RFI/2004-09/msg00093.html (8,365 bytes)

30. Re: [RFI] DirecTV TVI Issue (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 21 Sep 2004 18:06:55 -0500
Agreed on all counts. But don't rule out the need for ferrite chokes on those connections to solve pin 1 problems. :) Jim Brown K9YC _______________________________________________ RFI mailing list R
/archives//html/RFI/2004-09/msg00095.html (7,071 bytes)

31. Re: [RFI] 160 Meter Interference (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 06 Oct 2004 09:09:41 -0500
Yes. 10BaseT traffic on an ethernet cable will radiate strong carriers throughout the spectrum. Some I have identified are around 14,030, 21,052, and 28,014. There are also carriers on the low end of
/archives//html/RFI/2004-10/msg00012.html (10,374 bytes)

32. Re: Re: [RFI] 160 Meter Interference (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 06 Oct 2004 11:05:38 -0500
Now that you mention it, you remind me of related set of noise sources that I've found to be particularly nasty. They are the battery chargers for powered drills and screwdrivers. The noise they prod
/archives//html/RFI/2004-10/msg00017.html (9,204 bytes)

33. Re: Re: [RFI] 160 Meter Interference (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 06 Oct 2004 11:09:05 -0500
Sure you have -- they just aren't Yagi's. Look at any directional AM broadcast antenna array, or google on K9DX. I'd love to see photos of W8JI's farm. I'm sure others could cite some good examples.
/archives//html/RFI/2004-10/msg00018.html (8,901 bytes)

34. Re: [RFI] Ferrite Beads (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 18 Oct 2004 19:52:03 -0500
I have measured a LOT of ferrites, beads and otherwise, and I agree in general. BUT: Download and study the EXCELLENT pdf catalog from Fair Rite (google to find them), and study the app note on the u
/archives//html/RFI/2004-10/msg00051.html (9,082 bytes)

35. Re: [RFI] Ferrite Beads (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 19 Oct 2004 00:32:03 -0500
There are other options. Look at the Fair Rite catalog (study it carefully -- it takes hours to digest this stuff, and more hours to select the right parts). There are some VERY large clamp-ons of #3
/archives//html/RFI/2004-10/msg00058.html (8,923 bytes)

36. Re: [RFI] Ferrite Beads (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 21 Oct 2004 13:49:00 -0500
Unless 1) our labor is worth only a few pennies per hour or 2) you want to reinvent the wheel, or 3) you want to turn this into a science project, I STRONGLY suggest that you proceed as follows. 1) S
/archives//html/RFI/2004-10/msg00079.html (8,601 bytes)

37. Re: [RFI] Ferrite Beads (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 21 Oct 2004 23:45:04 -0500
Several people, myself included, who have spent MUCH time studying the behaviour of beads have suggested that you do the same, pointed you to the place where you can study them, and given you LOTS of
/archives//html/RFI/2004-10/msg00084.html (9,611 bytes)

38. Re: [RFI] RFI vs QRO? (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Fri, 22 Oct 2004 13:13:03 -0500
Two things at play. First, virtually all detection is square law, so once you above a threshold where detection takes place, a 6 dB increase in power will cause a 12 dB increase in the strength of th
/archives//html/RFI/2004-10/msg00093.html (9,315 bytes)

39. Ie: [RFI] Ferrite Beads (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Fri, 22 Oct 2004 13:27:40 -0500
I certainly did not belittle you nor anyone else. I did suggest (indirectly) that you were being lazy, expecting others to do your work for you. I did give you a bunch of specific suggestions about h
/archives//html/RFI/2004-10/msg00094.html (10,184 bytes)

40. Re: [RFI] RFI Services bullcrap smell test :) (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 26 Oct 2004 08:29:38 -0500
The comments from Eddie Edwards and others who have noted the significance of the loading on the BPL system highlight the important point also made by W4EF -- if my data is in conflict with solid sci
/archives//html/RFI/2004-10/msg00127.html (9,689 bytes)


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