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161. Topband: Noise cancelers (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Thu, 21 Mar 2002 08:43:41 -0500; 1.) Multiple noise sources can be nulled even if they are NOT the same waveform and level, as long as they come from the same direction and you have the sense antenna located near the main antenna..; /archives//html/Topband/2002-03/msg00197.html (8,461 bytes)
162. Topband: Re: MFJ power line noise receiver or alternatives? (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 22 Mar 2002 09:23:08 -0500; I used to handle occasional "we can't find it" problems for a few large utility companies, and designed some noise locating equipment for them. That does not surprise me! There is nothing that says e; /archives//html/Topband/2002-03/msg00208.html (9,984 bytes)
163. Topband: VP6DI (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Mon, 25 Mar 2002 06:45:21 -0500; VP6DI hears very very well. He was answering dozens of USA stations last night, but most of the USA he called never replied to him. That must be very frustrating for the DXpedition! It appears his tr; /archives//html/Topband/2002-03/msg00236.html (6,797 bytes)
164. Topband: 160 DX with limited resources (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 29 Mar 2002 07:16:12 -0500; All antennas work to some extent, if they are radiating. For example I have worked VK's that were mobile using 100 watts and small mobile antennas, and I have worked VK using the same. Does a well-c; /archives//html/Topband/2002-03/msg00253.html (7,754 bytes)
165. Topband: Opposition Statements to RM-10352 (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Thu, 7 Feb 2002 06:02:22 -0500; That isn't very smart. I'd strongly advise others to not spam the FCC website. DNS routing numbers are recorded, and they look for identical messages. The FCC is used to single individuals posting m; /archives//html/Topband/2002-02/msg00016.html (7,260 bytes)
166. Topband: Beacons (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Thu, 7 Feb 2002 07:14:37 -0500; You can look up the callsigns at: http://www.airnav.com/navaids/ Three letter identifiers, or the negative images of three letter identifiers, are airport non-directional beacons from below the broa; /archives//html/Topband/2002-02/msg00018.html (7,502 bytes)
167. Topband: NDB's and Fishing Beacons (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Thu, 7 Feb 2002 17:50:31 -0500; This topic comes up from time-to-time, and it is useful to understand how these beacons are constructed. Every transmitter I have seen (several dozen) has NOT had any type of low-pass filter in later; /archives//html/Topband/2002-02/msg00022.html (9,417 bytes)
168. Topband: Shortend Vertical model questions (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Sun, 10 Feb 2002 23:56:17 -0500; You ALWAYS want to use some sort of "hat" at the top of a vertical. If you make the capacitance of the hat large compared to the distributed capacitance in the vertical, the current will be uniform; /archives//html/Topband/2002-02/msg00038.html (9,107 bytes)
169. Topband: Shortend Vertical model questions (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 12 Feb 2002 07:57:19 -0500; Hi Tony, Most of the bandwidth in a loaded system (like a short vertical) comes from keeping reactance low, so system Q is low. Remember in a series resonant circuit, less reactance means lower Q. (; /archives//html/Topband/2002-02/msg00048.html (11,453 bytes)
170. Topband: Shortend Vertical model questions (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 12 Feb 2002 19:28:55 -0500; Yep, that's the main reason Roy included average gain in the windows version, so you could watch for errors. You do have to carefully look for weird results. Turns out average gain works especially; /archives//html/Topband/2002-02/msg00057.html (9,648 bytes)
171. Topband: Elevated beverage (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Thu, 14 Feb 2002 10:38:04 -0500; While it might hear something, I think you would be sadly disappointed if you compared that to a normal properly installed Beverage. The second wire will not act like a ground, nor do you want a "go; /archives//html/Topband/2002-02/msg00081.html (7,928 bytes)
172. Topband: Shortend Vertical model questions (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Thu, 14 Feb 2002 10:38:04 -0500; No, although it would be much better if the outer ends were connected...especially if the wires had to slope down. That would allow use of shorter wires in the tophat. It should also make a good 80; /archives//html/Topband/2002-02/msg00082.html (8,769 bytes)
173. Topband: Noise and reception (K6STI loop) (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Thu, 14 Feb 2002 10:38:03 -0500; One problem with models is we can sometimes design antennas that are impossible to build, because the sensitivity is low and the common-mode rejection we see using a "perfect" ground independent sour; /archives//html/Topband/2002-02/msg00083.html (9,166 bytes)
174. Topband: Noise and reception (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Sun, 17 Feb 2002 02:01:48 -0500; I don't think so Dave. I think it reasonable to point out as antennas are made smaller and smaller, they generally become more and more critical to build. It is also reasonable to point out that the; /archives//html/Topband/2002-02/msg00098.html (10,658 bytes)
175. Topband: Let's try stuff (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Sun, 17 Feb 2002 02:01:49 -0500; Hi Steve, The article actually states when radials are shortened and a loading coil is added, current in the radials is more evenly distributed and efficiency improves over (larger) systems with reso; /archives//html/Topband/2002-02/msg00099.html (9,859 bytes)
176. Topband: Noise and reception (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Sun, 17 Feb 2002 10:04:21 -0500; Hi David, Most DX signals, if not nearly all signals at a modest or greater distances, are vertically polarized when near earth. That is why our "noise" is substantially vertically polarized, and sig; /archives//html/Topband/2002-02/msg00103.html (14,949 bytes)
177. Topband: Noise and reception (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Mon, 18 Feb 2002 06:35:39 -0500; Hi Mike, That is my understanding also, although without an airplane or balloon I don't how to confirm it at very high heights. I can understand how the earth modifies the I guess it is like the para; /archives//html/Topband/2002-02/msg00110.html (9,743 bytes)
178. Topband: Let's try stuff (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 19 Feb 2002 20:01:06 -0500; ZL3REX works out much better on an inverted L than on a low horizontal. He lives in a valley without particularly good soil between high mountains, and has 30 radials on a 70 foot high Inverted L. N; /archives//html/Topband/2002-02/msg00116.html (11,025 bytes)
179. Topband: Re: Noise and reception (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Thu, 21 Feb 2002 10:07:38 -0500; If power line noise is severely attenuated so are low-angle signals that make up virtually ALL 160 meter DX signals. Of course at times during strong peaks or abnormal conditions like magnetic storm; /archives//html/Topband/2002-02/msg00124.html (11,023 bytes)
180. Topband: Polarisation and Power Coupling (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Sat, 23 Feb 2002 15:37:38 -0500; How do we explain the results of VK3ZL and ZL3REX, and other VK's and ZL's over the years, who are neither over good soil nor near the ocean, and who also are south? Some of the biggest and most con; /archives//html/Topband/2002-02/msg00146.html (8,172 bytes)

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