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References: [ +from:W8JI@contesting.com: 254 ]

Total 254 documents matching your query.

201. Re: [RFI] FW: Interference on TV using 2 meters (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Mon, 30 Oct 2006 08:22:16 -0500
I agree the Ham should not have been using 300 watts to access something 1/2 mile away, but the problem with TVI was 100% the cable operator's creation. When a licensed over-the-air service operatin
/archives//html/RFI/2006-10/msg00060.html (9,442 bytes)

202. Re: [RFI] RFI proof speakers (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Wed, 1 Nov 2006 15:53:15 -0500
Tim, The idea a bead or even a box of beads is always a major step just isn't accurate. A bead adds a series common mode impedance on the line, but we have no idea how much SHUNT impedance there is
/archives//html/RFI/2006-11/msg00007.html (8,647 bytes)

203. Re: [RFI] IN-band Filters (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Tue, 7 Nov 2006 18:26:30 -0500
You typically won't be able to have significant attenuation even with very good L/C components and stubs with their inherent low Q are out of the question. I was somewhat successful using toroids wi
/archives//html/RFI/2006-11/msg00018.html (7,596 bytes)

204. Re: [RFI] IN-band Filters (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Wed, 8 Nov 2006 06:00:06 -0500
I replied in the context of the question, HF filters. I have some 2 meter duplexers that work very well at 600kHz spacing, but they aren't quite practical to scale for 80 meter for the next field da
/archives//html/RFI/2006-11/msg00023.html (9,212 bytes)

205. Re: [RFI] IN-band Filters (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Wed, 8 Nov 2006 08:09:29 -0500
Most good capacitors are far above what you can do with the inductor. The highest Q reasonable size inductors I have ever measured just approach Q=1000. Those are large transmitting inductors used i
/archives//html/RFI/2006-11/msg00024.html (8,949 bytes)

206. Re: [RFI] 40M TVI problem (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Mon, 13 Nov 2006 22:04:37 -0500
Serge, I have corrected many dozens of TV systems near high power transmitters. One of them was within a few hundred feet of a large AM broadcast station. You could get burns and draw sparks from the
/archives//html/RFI/2006-11/msg00033.html (9,421 bytes)

207. Re: [RFI] 40m TVI (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Tue, 14 Nov 2006 13:09:45 -0500
Common mode chokes are FAR oversold and overused, and poorly understood. The function of a common mode choke is to reduce current flowing through an unwanted path. The effectiveness of the common mo
/archives//html/RFI/2006-11/msg00037.html (8,259 bytes)

208. Re: [RFI] wireless power at 6.4 MHz? (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Sat, 18 Nov 2006 11:53:25 -0500
Radiation is caused by time varying current in conductors. It is an entirely different mechanism than the induction fields. Anytime there is charge acceleration there is radiation. The only way to p
/archives//html/RFI/2006-11/msg00044.html (8,494 bytes)

209. Re: [RFI] wireless power at 6.4 MHz? (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Sun, 19 Nov 2006 07:57:52 -0500
Beware, doubletalk using uncommon words that really don't mean anything profound. It reminds me of statements like "we visited our mother's mother's house" instead of "we went to grandmas's" or most
/archives//html/RFI/2006-11/msg00054.html (9,525 bytes)

210. Re: [RFI] wireless power at 6.4 MHz? (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Sun, 19 Nov 2006 16:55:42 -0500
Of course you can, if you breach the shield. It just can't have a time-varying field that goes directly through the walls of the shield nor can it allow one field and not others to pass once the wal
/archives//html/RFI/2006-11/msg00062.html (8,818 bytes)

211. Re: [RFI] Haolgens AND . . . (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Sun, 19 Nov 2006 17:12:01 -0500
Same issue here. Despite well-shielded receiving systems and antennas hundreds of feet away from my shack I could not use any of the switching supplies I tried. I went to a conventional transformer.
/archives//html/RFI/2006-11/msg00063.html (8,005 bytes)

212. Re: [RFI] wireless power at 6.4 MHz? (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Mon, 20 Nov 2006 05:24:05 -0500
Anyone is free to believe anything they want, but the fact of the matter is if the time varying electric field is taken to zero the magnetic field also goes to zero. If we allow the time-vaying magne
/archives//html/RFI/2006-11/msg00066.html (9,179 bytes)

213. Re: [RFI] Haolgens AND . . . (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Mon, 20 Nov 2006 19:44:57 -0500
I just used an old filament transformer. Thanks to the audio-phools that like tube gear there are pages of filament transformers in Mouser's catalog, and of course there are control transformers of
/archives//html/RFI/2006-11/msg00072.html (8,401 bytes)

214. Re: [RFI] Lutron and RFI (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Mon, 20 Nov 2006 19:49:12 -0500
I'd be careful with that separate neutral suggestion. 1.) Wiring has to be to code, or it should be. 2.) Even if you break the neutral, you still have the hot lead and ground lead. Everything ties t
/archives//html/RFI/2006-11/msg00073.html (8,984 bytes)

215. Re: [RFI] [TowerTalk] Lutron and RFI (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Tue, 21 Nov 2006 19:00:02 -0500
They are always the same distance apart, assuming the wire is the same wire. Perhaps the assumption is the RFI is caused by differential currents, but in most cases for us they are either common mod
/archives//html/RFI/2006-11/msg00077.html (11,014 bytes)

216. Re: [RFI] RFI/EMI MAJOR Problems (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Thu, 30 Nov 2006 05:55:27 -0500
Bob, You've invested a great deal of time and money installing a less than ideal mix of toroids when the real problem is the horrible ground system on your vertical. Your antenna has virtually no gr
/archives//html/RFI/2006-11/msg00088.html (10,501 bytes)

217. Re: [RFI] GB> Re: [BOATANCHORS-TEMPE] Solid state 5R4's (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Wed, 6 Dec 2006 12:35:28 -0500
Nonsense. Electric and magnetic fields pass right through insulators. Only a closed Faraday cage or other suitable hardening would work, not that EMP protection means anything anyway. 73 Tom _______
/archives//html/RFI/2006-12/msg00015.html (7,351 bytes)

218. Re: [RFI] Low voltage lighting solid state "transformers" (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Sun, 17 Dec 2006 17:52:15 -0500
Technically any spurious emission that causes harmful interference to a licensed service is illegal regardless of absolute level. The ARRL also would have had to test the device in the actual workin
/archives//html/RFI/2006-12/msg00036.html (9,992 bytes)

219. Re: [RFI] Low voltage lighting solid state "transformers" (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Sun, 17 Dec 2006 18:21:33 -0500
My guess is if the device was **really** tested it would probably flunk emission standards. That's what I was saying in a nice way without saying it bluntly. I see a lot of cheap SMPS that fail. Man
/archives//html/RFI/2006-12/msg00039.html (9,202 bytes)

220. Re: [RFI] High Noise Levels on 80m (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Tue, 19 Dec 2006 22:21:13 -0500
Several factors enter the equation on 80 (and especially 160). Ground wave goes much further, antennas are closer to nearfield noise sources in terms of wavelength or antenna dimensions, and noise i
/archives//html/RFI/2006-12/msg00053.html (10,882 bytes)

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