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References: [ +from:w8ji@contesting.com: 254 ]

Total 254 documents matching your query.

221. Re: [RFI] RFI from an Alpha 87A linear (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Sat, 20 Jan 2007 08:09:49 -0500
Arcs like this are generally an open circuit or "poor connection" arc. It could be a HV rectifier diode burnt or cracked in half, a poor solder joint, or even corona or arcing from a current limited
/archives//html/RFI/2007-01/msg00009.html (8,060 bytes)

222. Re: [RFI] Identification Help Addendum (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Mon, 22 Jan 2007 08:52:32 -0500
... It's virtually certain it is not the power grid with that pattern. Things like fish tank heaters and other heating devices with thermostats that open the power line, door bell or other small tran
/archives//html/RFI/2007-01/msg00012.html (7,284 bytes)

223. Re: [RFI] Help on speed drive motor controller RFI (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Sun, 28 Jan 2007 22:13:14 -0500
Having had first hand experience with this exact problem, put me on the record as disagreeing. A controller can easily pass conducted emissions in CE or FCC testing by a wide margin and be horrible
/archives//html/RFI/2007-01/msg00025.html (9,046 bytes)

224. Re: [RFI] Help on speed drive motor controller RFI (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Mon, 29 Jan 2007 05:36:55 -0500
The EA5's post must have choked in a spam filter, but my points are twofold. 1.) even when the supply meets or exceeds FCC and CE specs, it can cause bad RFI problems. 2.) even if we don't see an ob
/archives//html/RFI/2007-01/msg00027.html (8,807 bytes)

225. Re: [RFI] Help on speed drive motor controller RFI (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Mon, 29 Jan 2007 18:07:40 -0500
What type of controller do you have? Who makes it? What is the model? They are all cureable, and many times all it takes is a shield box with good filters. It is very easy to knock HF noise down a h
/archives//html/RFI/2007-01/msg00033.html (9,081 bytes)

226. Re: [RFI] Help on speed drive motor controller RFI (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Tue, 30 Jan 2007 05:00:33 -0500
I've been through that too with almost identical controllers, and the problem is getting electricians to understand shielding. The motor and leads are the big issues. They carry the high current hig
/archives//html/RFI/2007-01/msg00036.html (10,406 bytes)

227. Re: [RFI] FM RFI? (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Mon, 19 Feb 2007 12:59:19 -0500
The radio doesn't know or care if it is FM, AM, SSB, or CW. When the noise is strong enough we will hear it. FM can "capture" with a strong enough signal and a low level noise or low interference le
/archives//html/RFI/2007-02/msg00052.html (7,724 bytes)

228. Re: [RFI] TV Line amplifiers (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Fri, 13 Apr 2007 21:43:12 -0400
Rod, Assuming you are using them for TV applications there are many good line amps. I used to do systems engineering for a company in Ohio that had dozens of head ends... with some very close to bro
/archives//html/RFI/2007-04/msg00016.html (9,132 bytes)

229. Re: [RFI] Noise is everywhere (was Solar Arrays) (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Thu, 10 May 2007 05:31:24 -0400
Sorry, but the noise in the city and suburbs affects the noise far away in the country and it is now several dB nosier even in remote areas compared to 20 years ago. 73 Tom _________________________
/archives//html/RFI/2007-05/msg00008.html (7,053 bytes)

230. Re: [RFI] Noise in 2007 RHS-TV (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Mon, 14 May 2007 14:35:52 -0400
The noise in modern diesels is almost always the injector solenoids. All of the systems I've seen turns each injector on at the appropriate times (near the top of the compression stroke). The inject
/archives//html/RFI/2007-05/msg00019.html (8,862 bytes)

231. Re: [RFI] Noise in 2007 RHS-TV (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Mon, 14 May 2007 14:38:11 -0400
The reason the noise disappears is the injectors are often not even opened when you lift you foot until the idle speed is reached. That saves fuel. _______________________________________________ RF
/archives//html/RFI/2007-05/msg00020.html (8,004 bytes)

232. Re: [RFI] 115 KV Lines (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Tue, 22 May 2007 10:46:41 -0400
The problem with a 115kV line is if anything ever goes wrong they will almost never want to fix it. Also, in my experience, don't count on hearing well in the direction of the line. There is always
/archives//html/RFI/2007-05/msg00028.html (8,675 bytes)

233. Re: [RFI] [TowerTalk] 115 KV Lines (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Tue, 22 May 2007 12:19:02 -0400
Is this a well known phenomena? Is it specific to HV lines? If so, this may be something to consider if you get lots of rain in your It happens all the time. Also dirt on insulators or foggy damp mor
/archives//html/RFI/2007-05/msg00032.html (8,881 bytes)

234. Re: [RFI] [TowerTalk] 115 KV Lines (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Wed, 23 May 2007 13:41:07 -0400
I have a good friend who swears the new HV transmission lines near his house don't affect him. The same receiver at my house that reads S-0 on an 80 meter dipole in the daytime reads S-7 at his house
/archives//html/RFI/2007-05/msg00039.html (9,580 bytes)

235. Re: [RFI] RFI from Astron power supply (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Fri, 25 May 2007 20:50:43 -0400
RFI is like describing pain, every station has a different tolerance for RFI just like every person has a different tolerance for pain. At my station http://www.w8ji.com/station_ground.htm: 1.) feed
/archives//html/RFI/2007-05/msg00049.html (8,886 bytes)

236. Re: [RFI] Noisey PSU (Laptop) on HF Decodeing (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Tue, 29 May 2007 20:36:17 -0400
But of course we all know it takes two to tango!!! Not only must the PS make noise, the noise must somehow get into the receiving system. Every fast efficient switching supply in the world makes noi
/archives//html/RFI/2007-05/msg00063.html (8,634 bytes)

237. Re: [RFI] Identify this pole hardware (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Wed, 30 May 2007 12:57:40 -0400
The CATV line is the second line up. You can see the splitters on that line in picture 3. The black boxes are on what appears to be the telephone line, and they have a standard numbering system used
/archives//html/RFI/2007-05/msg00069.html (7,313 bytes)

238. Re: [RFI] Identify this pole hardware (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Wed, 30 May 2007 14:36:42 -0400
In the 70's I did consulting work and handled overflow from a few utilities voltage investigation units. While it has been many years ago, the most common cause of "big bangs" and light blinks after
/archives//html/RFI/2007-05/msg00075.html (9,612 bytes)

239. Re: [RFI] RFI from Astron power supply (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Mon, 4 Jun 2007 11:51:39 -0400
.....and what is always most important is HOW the RFI is getting into the system. My own experience is that electronic ballasts are generally noisier, not less noisy. The older conventional systems a
/archives//html/RFI/2007-06/msg00002.html (9,366 bytes)

240. Re: [RFI] Long distance grounding (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Mon, 11 Jun 2007 21:22:54 -0400
Oh boy! One of my favorites! :-) The center conductor does nothing at all Dennis. You can throw it away. Same for the capacitors. Skin effect keeps all the current on the outside of the shield. Sinc
/archives//html/RFI/2007-06/msg00010.html (9,063 bytes)

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