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381. Topband: Receive Antenna F/B (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Mon, 16 Oct 2000 08:33:32 -0400; It depends WHERE you ground or float the antenna, and how long the antenna is. I'm sure Mauri was speaking of the specific case of a 1/4 wl inverted L and disconnecting at the antenna....not in the; /archives//html/Topband/2000-10/msg00096.html (7,768 bytes)
382. Topband: Beverage Length (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Tue, 17 Oct 2000 08:20:46 -0400; Hi Ford, The tilt is caused by the fact the wave itself is not lightspeed near earth. Maybe I'm missing something, but I don't see how the optimum length can be selected without considering the chang; /archives//html/Topband/2000-10/msg00104.html (10,431 bytes)
383. Topband: receiving antennas (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Wed, 18 Oct 2000 08:27:50 -0400; On receiving, within the limits of internal noise of a system, gain does not matter. Neither does efficiency. If two antennas are compared on the basis of gain, or take-off angle, the result is basic; /archives//html/Topband/2000-10/msg00108.html (9,561 bytes)
384. Topband: Re: Beverage Length (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Thu, 19 Oct 2000 08:14:37 -0400; Hi Jan, I don't follow that line of thought. Even a 1 WL Beverage has good response along the ground for groundwave, and at low wave angles for skywave. A 4 WL Beverage is about useless because the p; /archives//html/Topband/2000-10/msg00123.html (8,571 bytes)
385. Topband: N0OQW Beverage Spreadsheet (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Wed, 18 Oct 2000 15:04:43 -0400; Hi Ford, I suspect almost everyone is keenly interested in receiving antennas. That's been my experience. Certain lengths can create extra useful nulls if you have undesired signals (that includes th; /archives//html/Topband/2000-10/msg00124.html (10,153 bytes)
386. Topband: Re: Beverage Length (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Fri, 20 Oct 2000 10:51:27 -0400; Hi Jim I don't buy into that high angle stuff for a minute! I have many transmitting antennas including dipoles at 300 feet, and ground mounted verticals. The dipoles (at best) tie the ground mounted; /archives//html/Topband/2000-10/msg00131.html (8,841 bytes)
387. Topband: remotely-controlled Beverage termination (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Fri, 20 Oct 2000 11:17:46 -0400; Your applications are totally different also. You are trying to null a signal station causing QRM, while Dave is trying to establish high S/N without regard to depth of a null in one specific direct; /archives//html/Topband/2000-10/msg00132.html (8,612 bytes)
388. Topband: Good soil vs bad soil (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Fri, 20 Oct 2000 22:52:31 -0400; Hi Greg, That's the least of the problems Greg. What is measured at 60 Hz (or 50 Hz) has almost nothing to do with how the soil behaves at 2 MHz. The skin depth on 160 meters can be as deep as 30 fee; /archives//html/Topband/2000-10/msg00136.html (7,753 bytes)
389. Topband: receiving antennas (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Sat, 21 Oct 2000 08:23:50 -0400; Eznec exports a pattern table that may somehow be able to be imported into a spreadsheet, but don't ask me how to do that. One problem with Eznec is it doesn't plot groundwave. That means low angle; /archives//html/Topband/2000-10/msg00139.html (8,564 bytes)
390. Topband: DOUBLED RADIALS (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Sun, 29 Oct 2000 06:27:08 -0500; 1/4wl of wire in a 1/8th wl long area is a 1/8 wl radial. The primary "job" of a radial is to spread the electric (voltage) and magnetic (current) fields over a large area, so losses are reduced in; /archives//html/Topband/2000-10/msg00166.html (7,681 bytes)
391. Topband: Beverages (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Mon, 30 Oct 2000 13:44:18 -0500; I just measured some signal levels this weekend, so I'll post a few of the levels because other may be able to use the information to estimate signal levels they might have in their antennas. Once yo; /archives//html/Topband/2000-10/msg00174.html (8,264 bytes)
392. Topband: Bizarre conditions 10/28 on top band (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Mon, 30 Oct 2000 13:44:18 -0500; I don't think conditions were so bizarre. It was a typical SSB contest, where everyone spends too much time calling and the QRM is the limiting factor. The band was open a long time, and seemed stabl; /archives//html/Topband/2000-10/msg00175.html (8,227 bytes)
393. Topband: Bizarre conditions 10/28 on top band (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Mon, 30 Oct 2000 20:11:56 -0500; I keep watching the A, K and SFI along with the Aurora numbers. Nothing ever seems to make sense. The days when I figure it isn't worth trying are often the best, many days when the A and K are low; /archives//html/Topband/2000-10/msg00177.html (9,054 bytes)
394. Topband: Polarization of Man Made Noise? (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Tue, 31 Oct 2000 07:53:20 -0500; You hit the nail on the head Mike. The reasons local noise sources are predominately vertically polarized are because horizontally polarized signals are radiated and received at high angles by most "; /archives//html/Topband/2000-10/msg00182.html (9,970 bytes)
395. Topband: JA Operations (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Fri, 1 Sep 2000 22:47:14 -0400; I hope the JA's operate split, and move the W's to harmless frequencies. Things will be much worse now working JA from the USA, if operating simplex. There are several dozens of JA's on, and dozens; /archives//html/Topband/2000-09/msg00008.html (6,995 bytes)
396. Topband: 1.5:1 Bandwidth of shunt fed towers. (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Tue, 5 Sep 2000 13:52:26 -0400; Two main factors enter the equation: 1.) How rapidly the radiator changes impedance with frequency. 2.) The Q of the matching system. The radiator is something we are probably "stuck with" and can't; /archives//html/Topband/2000-09/msg00020.html (8,911 bytes)
397. Topband: shunt-fed bandwidth (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Wed, 6 Sep 2000 19:26:23 -0400; Hi Don, I hope you don't mind my pointing out something. While your suggestions are all good ones, I can site cases where the rules are broken..... Consider a case of a single (or small number of) el; /archives//html/Topband/2000-09/msg00025.html (8,628 bytes)
398. Topband: Hybrid Coupler (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Fri, 8 Sep 2000 08:49:20 -0400; This may be unpopular, but I never use hybrid couplers. When an antenna is phased, you typically need equal currents in the elements. A hybrid coupler or splitter does nothing to guarantee that. It; /archives//html/Topband/2000-09/msg00033.html (8,797 bytes)
399. Topband: Hybrid Coupler (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 8 Sep 2000 10:55:08 -0400; Brand new HT57s cost about $15-20 from HEC, if they will sell to you. The problem with higher value capacitors is they have high ESR, and heat. They also have high capacitance drift with temperature; /archives//html/Topband/2000-09/msg00035.html (8,725 bytes)
400. Topband: Making low wires more visible de K0FF (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Fri, 8 Sep 2000 17:12:45 -0400; Another cure is to not slope the ends, and bring them down along a thick obstacle. Six or ten feet of vertical drop is six or ten feet of drop, whether in one small area or a 60 foot length. The res; /archives//html/Topband/2000-09/msg00037.html (7,932 bytes)

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