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261. Topband: Collins 75A4 (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Thu, 16 Aug 2001 21:26:52 -0400; I want to measure every kind of receiver I can find on 160 meters. It only takes about a half-hour a receiver (or transceiver). If anyone is in the Macon Georgia area, the measurements are free and; /archives//html/Topband/2001-08/msg00066.html (7,366 bytes)
262. Topband: Collins 75A4 (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 17 Aug 2001 21:46:19 -0400; The factor you are looking for is probably ringing and group delay errors in filters, which can mess up some receivers when "rough" noise is present with weak signals. Since the tests indicated poor; /archives//html/Topband/2001-08/msg00074.html (8,757 bytes)
263. Topband: HF2V 160m kit doorknob caps (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Thu, 23 Aug 2001 17:48:29 -0400; If someone can FAX me the layout of the Butternut, I'd like to calculate the worse case voltage and current through the capacitors for 160m. Those big caps have moisture absorption problems in ampli; /archives//html/Topband/2001-08/msg00095.html (7,323 bytes)
264. Topband: Antennas (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Mon, 27 Aug 2001 08:43:21 -0400; Hi Larry, Unless we A-B an antenna time and time again against a known and stable reference and average the results, small or even modest changes are lost in the data clutter. I never looked at data; /archives//html/Topband/2001-08/msg00114.html (9,897 bytes)
265. Topband: Antennas (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Mon, 27 Aug 2001 17:07:10 -0400; Hi Larry, The best thing with any of this is to model the antenna. Not at all. Log entries reflect propagation, equipment, noise , and many other things including the mood of the operator. There is s; /archives//html/Topband/2001-08/msg00123.html (9,929 bytes)
266. Topband: Antennas (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Mon, 27 Aug 2001 18:07:47 -0400; Hi Mario, I'm nearly out of time for this, but I'd hate to see anyone sell an idea that has merit short. While no one can dispute long hat wires near ground are a problem, we should not neglect compa; /archives//html/Topband/2001-08/msg00124.html (9,455 bytes)
267. Topband: Drooping top hats (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 28 Aug 2001 18:49:55 -0400; The most detailed and accurate loading inductor text readily available to amateurs appears in the chapter "Reactive Elements and Impedance Limits" in Kuecken's book "Antennas and Transmission Lines"; /archives//html/Topband/2001-08/msg00140.html (8,880 bytes)
268. Topband: 160M Short Verticals (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Wed, 29 Aug 2001 13:35:30 -0400; Good idea for limited space, but we should remember this. When the antenna has a large hat capacitance, compared to the distributed capacitance of the structure, there is no reason at all to put the; /archives//html/Topband/2001-08/msg00145.html (8,120 bytes)
269. Topband: 160M Short Verticals (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Thu, 30 Aug 2001 09:27:47 -0400; Hi John, If the book says that, it is not correct. Originally proposed in 1920, you can find this system analyzed in Jasik's "Antenna Engineering Handbook" 1st edition page 19-9. Ground loss remain c; /archives//html/Topband/2001-08/msg00149.html (9,748 bytes)
270. Topband: 160M Short Verticals (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Thu, 30 Aug 2001 19:05:12 -0400; Hi John, The point I tried to make is that each individual ground system has to be smaller than optimum, and *isolated*, with no way to connect them for a multi-drop system to help. In other words, i; /archives//html/Topband/2001-08/msg00154.html (8,287 bytes)
271. Topband: Feed Line (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Mon, 11 Jun 2001 22:07:31 -0400; Of course we all know there are impedance transformation problems you might run into. A 30 ohm antenna through 1/4 wl of 450 ohm line would be 6750 ohms at the tuner end of things. Most tuners are p; /archives//html/Topband/2001-06/msg00021.html (7,944 bytes)
272. Topband: re:hytower (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Thu, 31 May 2001 20:26:35 -0400; Hy-Gain (after the move) still has all the original tooling and parts except for the tower, and MFJ has decided they should look into substituting an aluminum tower from one of the aluminum tower co; /archives//html/Topband/2001-05/msg00001.html (7,227 bytes)
273. Topband: 160 vertical, radials and beverages (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Mon, 7 May 2001 16:42:07 -0400; Mutual coupling is not the issue. The radials provide the other terminal for the feedline to "push" against. Unless the feedline is radiating, you will have exactly the same current into the ground; /archives//html/Topband/2001-05/msg00012.html (9,565 bytes)
274. [Topband: Lightning Arrestor] (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Sun, 13 May 2001 21:33:57 -0400; I think you are using RMS voltage. The nominal peak voltage is actually 1.414 times the RMS voltage you gave above, plus we need margin for tolerances and transients. Many rigs overshoot on the init; /archives//html/Topband/2001-05/msg00027.html (8,707 bytes)
275. Topband: Beverages, Lightning and Moose (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Wed, 16 May 2001 09:54:42 -0400; I have miles of cables and dozens of switching relays spread over a large area. Making matters worse, I have some very tall structures attracting occasional hits. Because of the number of cables and; /archives//html/Topband/2001-05/msg00033.html (7,945 bytes)
276. Topband: Common mode filters...help (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 22 May 2001 04:54:49 -0400; When the frequency is somewhat low it is almost always more cost effective to use a toroid rather than a string of beads...assuming the target is a high impedance. That's because impedance increases; /archives//html/Topband/2001-05/msg00039.html (8,146 bytes)
277. Topband: Common mode filters...help (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Tue, 22 May 2001 18:04:08 -0400; I think I misunderstood this connection. I assumed this described a bifilar choke of some sort, and not a single winding choke! A choke only on the shield would "disconnect" the shield and make thing; /archives//html/Topband/2001-05/msg00040.html (7,483 bytes)
278. Topband: FT1000MP click reduction (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Thu, 24 May 2001 14:41:07 -0400; The FT1000MP is entirely different than the 1000D or 1000. It keys the carrier after the filters, not before them. The problem with the MP is entirely due to the waveshape of the envelope near the ma; /archives//html/Topband/2001-05/msg00050.html (8,145 bytes)
279. Topband: 160 Meter Antenna Help (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Fri, 25 May 2001 06:05:43 -0400; "Capacitive coupling" is maximum near the voltage point of an antenna. Moving the voltage near earth and concentrating it around one single radial is generally not a good idea. Ground losses are a co; /archives//html/Topband/2001-05/msg00052.html (8,274 bytes)
280. Topband: Re: [CQ-Contest] FT1000MP click reduction - CORRECTION (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 25 May 2001 07:11:59 -0400; N4ZR replied: Too much time looking at surface mount boards! C2148 is the correct capacitor to change. C2148 is a tiny .0047uF chip near T2018. I soldered a .1 uF chip directly across it, but a leade; /archives//html/Topband/2001-05/msg00053.html (7,736 bytes)

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