- 301. Re: [RFI] Smoke and CO alarms update (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Mon, 08 Oct 2007 10:34:42 -0700
- A better coax choke at the antenna feedpoint could further reduce the RF on the feedline, which MIGHT be part of the coupling to equipment having problems. See http://audiosystemsgroup.com/RFI-Ham.pd
- /archives//html/RFI/2007-10/msg00023.html (8,968 bytes)
- 302. [RFI] Global Warming and Ecology (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Sat, 20 Oct 2007 07:26:41 -0700
- Those doing the disputing don't have science on their side. I see those doing the disputing as coming from one or more of the following places: May I remind those here of the scientific method -- stu
- /archives//html/RFI/2007-10/msg00098.html (10,310 bytes)
- 303. Re: [RFI] 120Hz period noise ID (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Tue, 30 Oct 2007 12:09:27 -0700
- I suspect you're right that this may be a "two-problem problem." Look for one (or more) of the following: 1) An extra bond between neutral and ground at some point. NEC requires ONE, and ONLY ONE, bo
- /archives//html/RFI/2007-10/msg00136.html (9,494 bytes)
- 304. Re: [RFI] 120Hz period noise ID (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Tue, 30 Oct 2007 23:18:56 -0700
- The "electronic transformers" are NASTY RFI generators -- they're really switching power supplies. The only fix I know of (short of replacing them) is to add a REALLY GOOD RF filter between them and
- /archives//html/RFI/2007-10/msg00141.html (8,590 bytes)
- 305. Re: [RFI] Testing & Comparing Compact Fluorescents? (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Wed, 31 Oct 2007 10:59:29 -0700
- About a year ago, I replaced almost all of my incandescent bulbs with Phillips Marathon CF's that I bought at Costco. I checked very carefully for RFI, and have never heard any. The only failure I've
- /archives//html/RFI/2007-10/msg00153.html (9,136 bytes)
- 306. Re: [RFI] [TowerTalk] Testing & Comparing Compact Fluorescents? (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Wed, 31 Oct 2007 19:48:45 -0700
- I suspect you are right, Rick. Jim _______________________________________________ RFI mailing list RFI@contesting.com http://lists.contesting.com/mailman/listinfo/rfi
- /archives//html/RFI/2007-10/msg00155.html (8,964 bytes)
- 307. Re: [RFI] RFI Resistant (and high quality) Computer Speakers??? (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Tue, 06 Nov 2007 19:25:43 -0700
- What's your budget? At every pro audio trade show, I walk around with my 2m/440 talkie, seeing what mischief I can cause in the gear on display on the floor. So far, I've never seen ANY loudspeaker w
- /archives//html/RFI/2007-11/msg00015.html (7,790 bytes)
- 308. Re: [RFI] RFI Resistant (and high quality) Computer Speakers??? (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Wed, 07 Nov 2007 19:57:45 -0800
- I did not write that. N6KJ did. Jim _______________________________________________ RFI mailing list RFI@contesting.com http://lists.contesting.com/mailman/listinfo/rfi
- /archives//html/RFI/2007-11/msg00019.html (7,817 bytes)
- 309. Re: [RFI] 10m RFI "white noise hiss" (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Sat, 10 Nov 2007 13:24:33 -0800
- I would expect that most good line filters would also work -- IF properly installed, and IF the trash is being radiated by the power line. BUT: the trash may also be radiated by the power cord (betwe
- /archives//html/RFI/2007-11/msg00029.html (7,843 bytes)
- 310. Re: [RFI] Car laptop adaptors (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Sun, 11 Nov 2007 16:45:54 -0800
- My experience is that my IBM T-series laptops run on a direct connection to the car if it's running. I've tried running them from a 12V battery (not being charged), and the charge regulator inside th
- /archives//html/RFI/2007-11/msg00035.html (8,184 bytes)
- 311. Re: [RFI] Non-transmitting tower causes RFI/EMI? (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Wed, 14 Nov 2007 13:33:27 -0800
- On Tue, 13 Nov 2007 21:33:41 -0800, digital-conjurers@roadrunner.com wrote: Yes, this is a fundamental problem. Attempting coherent discussions with a person who is ignorant about the topic at hand a
- /archives//html/RFI/2007-11/msg00061.html (9,549 bytes)
- 312. Re: [RFI] Non-transmitting tower causes RFI/EMI? (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Wed, 14 Nov 2007 13:38:32 -0800
- Huh? While it is out of order to take this discussion into politics (as you have done), an obviously biased mis-statement of facts cannot be allowed to pass unchallenged. To accuse Mr. Gore of being
- /archives//html/RFI/2007-11/msg00062.html (8,953 bytes)
- 313. Re: [RFI] Non-transmitting tower causes RFI/EMI? (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Wed, 14 Nov 2007 21:29:55 -0800
- Huh? How does what I said translate to what you wrote? My comment was a response to the guy with the uneducated neighbor who blamed his antennna for things it can't possibly do. Granted it's a common
- /archives//html/RFI/2007-11/msg00067.html (9,677 bytes)
- 314. Re: [RFI] Elevator noise (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Wed, 21 Nov 2007 07:56:21 -0800
- What you have encountered are variable speed drive motors. The controllers for these motors take AC (lots of it, enough to run the motors), rectify it, then pulse modulate it and vary the width of th
- /archives//html/RFI/2007-11/msg00071.html (9,306 bytes)
- 315. Re: [RFI] OT? Why Does 1450 Wobble & 970 Not? (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Wed, 21 Nov 2007 12:56:03 -0800
- Yes. 1450 is one of several local channels (1230, 1240, and 1340 are the others). The "wobble" described in the original post is most likely the very low frequency heterodyne (beat) between one domin
- /archives//html/RFI/2007-11/msg00078.html (7,449 bytes)
- 316. Re: [RFI] QRN Problem? (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Mon, 03 Dec 2007 10:50:37 -0800
- Hi Randy, Your noise level is not unusually high for someone living in a town or city. Indeed, it's lower than I sometimes experienced in a Chicago residential neighborhood! Noise comes from many sou
- /archives//html/RFI/2007-12/msg00001.html (9,395 bytes)
- 317. Re: [RFI] Franklin Electric Sub Drive 150 RFI? (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Sun, 09 Dec 2007 22:47:11 -0800
- Rich, My guess is that the controller is a variable speed drive for the motor. That type of controller is well known as a nasty noise source. I've talked a bit about them in my RFI tutorial. It is wo
- /archives//html/RFI/2007-12/msg00023.html (7,996 bytes)
- 318. Re: [RFI] RFI: TORCHIERE TORTURE! (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Thu, 20 Dec 2007 22:57:03 -0800
- house. Agree. house must have RF all through it. Agree. Agree NO, NO, NO! The EARTH is important ONLY for lightnihg safety. It has NOTHING to do with the operation of an antenna or keeping RF out of
- /archives//html/RFI/2007-12/msg00038.html (9,155 bytes)
- 319. Re: [RFI] PC Power Supply Noise (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Wed, 26 Dec 2007 16:49:15 -0800
- Yes. For a line filter to be effective, there must be a very short shield and circuit return for the filter back to the shielding enclosure of the computer. Any exposed wiring between the filter and
- /archives//html/RFI/2007-12/msg00063.html (7,618 bytes)
- 320. Re: [RFI] PC Power Supply Noise (score: 1)
- Author: "Jim Brown" <jim@audiosystemsgroup.com>
- Date: Wed, 26 Dec 2007 19:17:44 -0800
- On Wed, 26 Dec 2007 19:43:33 -0600, W0UN -- John Brosnahan quotes K6NA: Because at RF, resistance is a relatively small part of the braid's impedance and inductance reactance is the major component,
- /archives//html/RFI/2007-12/msg00066.html (7,620 bytes)
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