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241. Re: [RFI] Tin roof under yagi ... RFI? (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Sun, 21 Mar 2021 15:47:13 +0000; RFI: Only if you have a near-by strong transmitter and wind that rattles the joints between sections of the tin roof. PATTERN: I'd suggest doing a model of the setup using any of the following: EZNEC; /archives//html/RFI/2021-03/msg00049.html (8,312 bytes)
242. Re: [RFI] Tin roof (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Sun, 21 Mar 2021 21:28:25 +0000; We have a steel roof. It's In sections about 2-feet wide and long 40 to 50 feet long. I was a bit concerned about noise in a good wind (which we regularly get!). No problem. And it makes a wonderful; /archives//html/RFI/2021-03/msg00059.html (8,346 bytes)
243. Re: [RFI] New Interference at kk0sd (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Mon, 22 Mar 2021 01:12:57 +0000; While the RSP1 will get the job done, it has limitations I won't go into. The AirSpy products are far superior to those 'others' within the price range. No connection other than having used both offe; /archives//html/RFI/2021-03/msg00069.html (10,269 bytes)
244. Re: [RFI] New Interference at kk0sd (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Mon, 22 Mar 2021 17:21:36 +0000; We recently found a faulty lightning 'arrestor' on a pole by using both the MFJ device and a small shielded loop (easy home brew project) into a battery-powered receiver. We had two of us in the fiel; /archives//html/RFI/2021-03/msg00082.html (16,345 bytes)
245. Re: [RFI] New Interference at kk0sd (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Mon, 22 Mar 2021 22:25:14 +0000; Attached is the 0.5-Meter shielded loop I built for DFing and ELF reception (in addition to the 2-Meter shielded loop I have up on the hillside). It's pretty simple. Dave - WØLEV -- *Dave - WØLEV* *J; /archives//html/RFI/2021-03/msg00085.html (21,876 bytes)
246. Re: [RFI] New Interference at kk0sd (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Tue, 23 Mar 2021 22:29:44 +0000; Another trick I've used in DFing interference is to construct a shortened helically wound dipole on a wooden dowel stick. One can easily resonate it for the frequency of interest by extending / trimm; /archives//html/RFI/2021-03/msg00098.html (32,285 bytes)
247. Re: [RFI] New Interference at kk0sd (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Wed, 24 Mar 2021 20:22:32 +0000; While not my design, this works wonders for the small untuned loops. I used a 2N5109. Don't fudge too much on the component values as the author points out the values presented yield good dynamic ran; /archives//html/RFI/2021-03/msg00112.html (37,292 bytes)
248. Re: [RFI] New Interference at kk0sd (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Fri, 26 Mar 2021 16:23:03 +0000; I'll comment further on my 0.5-Meter shielded loop. What's different is that I have five turns of conducter inside the copper tubing. I've found very little to nothing online for multi-turn internal; /archives//html/RFI/2021-03/msg00122.html (14,940 bytes)
249. Re: [RFI] RF Exposure Radiation Study (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Sun, 28 Mar 2021 16:44:54 +0000; You might procure a RF field strength meter with appropriate sensor heads and go into business. Narda as a supplier comes to mind, but someone likely has bought them out since I had one of theirs. Th; /archives//html/RFI/2021-03/msg00134.html (8,846 bytes)
250. Re: [RFI] Common Mode In-Shack Choke (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Wed, 7 Apr 2021 22:01:59 +0000; I have used RG-142 for the purpose. It is high-power Teflon center insulated with double shield. All conductors are silver plated. It will take a kW at HF. Dave - WØLEV -- *Dave - WØLEV* *Just Let Da; /archives//html/RFI/2021-04/msg00027.html (8,476 bytes)
251. Re: [RFI] Old wives tail, or true? (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Fri, 9 Apr 2021 17:19:49 +0000; I see we can attach something to email within this group. Therefore, please see the attachment. My antennas are deployed in a relatively RF quiet area well outside cities and in the county where I do; /archives//html/RFI/2021-04/msg00048.html (13,935 bytes)
252. Re: [RFI] Old wives tail, or true? (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Fri, 9 Apr 2021 19:08:59 +0000; Losses can get quite high in a common mode choke in a line that is mismatched to it's load. Count on destructive failure with high power. Yes, the average chokes embodied in the average amateur marke; /archives//html/RFI/2021-04/msg00050.html (19,050 bytes)
253. Re: [RFI] Old wives tail, or true? (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Fri, 9 Apr 2021 21:56:00 +0000; The input of the L-Network matching network is common mode. The output of the matching network is common mode. The common mode choke belongs at the matching network output which is common mode and te; /archives//html/RFI/2021-04/msg00055.html (14,349 bytes)
254. Re: [RFI] Old wives tail, or true? (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Fri, 9 Apr 2021 22:07:15 +0000; Who wrote EMC guru"? It wasn't me!!!! I just stated at the end that I had taken the referred Henry Ott courses at HP's expense and the Howard Johnson's 4-day course at the expense of StorageTek. I do; /archives//html/RFI/2021-04/msg00056.html (11,585 bytes)
255. Re: [RFI] Wireless Power Transfer with electric vehicles (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Sun, 11 Apr 2021 18:27:35 +0000; With FCC having RF exposure "safety" issues with low power wireless chargers - we have to measure RF field strength as a regulatory issue, now - I certainly can envision these 20 kW beomyths coming u; /archives//html/RFI/2021-04/msg00071.html (15,383 bytes)
256. Re: [RFI] I could see the arcs with binoculars last night! (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Sun, 11 Apr 2021 20:10:38 +0000; Absolutely excellent report and technique. This should go into the files section as an example of how to go about this business. Well done! Excellent report and documentation. Email this to your powe; /archives//html/RFI/2021-04/msg00076.html (8,817 bytes)
257. Re: [RFI] Wireless Power Transfer with electric vehicles (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Sun, 11 Apr 2021 20:12:56 +0000; My hope is that it is too expensive for most of us. Does it have FCC blessing. All I see are European installations. Dave - WØLEV -- *Dave - WØLEV* *Just Let Darwin Work* ____________________________; /archives//html/RFI/2021-04/msg00077.html (17,123 bytes)
258. Re: [RFI] I could see the arcs with binoculars last night! (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Sun, 11 Apr 2021 21:23:42 +0000; Isn't retirement wonderful!!?? Dave - WØLEV -- *Dave - WØLEV* *Just Let Darwin Work* _______________________________________________ RFI mailing list RFI@contesting.com http://lists.contesting.com/ma; /archives//html/RFI/2021-04/msg00084.html (10,642 bytes)
259. Re: [RFI] Wireless Power Transfer with electric vehicles (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Sun, 11 Apr 2021 23:50:16 +0000; EVs: they are also ignoring the power must be generated somewhere, somehow, in some manner, using multiple natural resources. The EV power budget is a loser when the womb-to-tomb analysis of electric; /archives//html/RFI/2021-04/msg00093.html (9,669 bytes)
260. Re: [RFI] Flag Pennant loop - Tiny SA use (score: 1): Author: David Eckhardt <davearea51a@gmail.com>; Date: Mon, 12 Apr 2021 23:49:18 +0000; Don't forget the average 'lab' SA has a typical noise figure around 18 to 22 dB. All need a preamp for reasonable sensitivity. Many of the lab instruments today are being marketed with a built-in pre; /archives//html/RFI/2021-04/msg00120.html (8,876 bytes)

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