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101. Topband: Flag Xfmr Measurements End Game (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Mon, 23 Sep 2002 07:44:25 -0400; Bob, (You may want to crosspost this the the Flag group.) We have to be very careful adding reactances in series with the common-mode impedance of a system to reduce unwanted current. In many cases,; /archives//html/Topband/2002-09/msg00162.html (8,626 bytes)
102. Topband: 160m conditions - before and after solar peak (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Mon, 23 Sep 2002 08:47:09 -0400; I don't think we are that long after the peak. More like a few months, if that. The flux and sunspots were really high just a week ago. But that isn't the problem, because some of the best openings; /archives//html/Topband/2002-09/msg00163.html (8,017 bytes)
103. Topband: 259B, CIA-HF and Cablemate? (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Mon, 23 Sep 2002 15:05:47 -0400; You have to load the vertical, and swamp it with a series resistor if you want any reliable performance. You could use a source follower FET buffer. A J310 biased at about 50mA has about 75 ohms sou; /archives//html/Topband/2002-09/msg00169.html (7,583 bytes)
104. Topband: Inverted Ground Plane (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Wed, 25 Sep 2002 13:53:52 -0400; I'm not sure exactly what feed system is being described, but with the original system he was talking about and inverted groundplane. Say we build a groundplane antenna, either inverted or not, and; /archives//html/Topband/2002-09/msg00182.html (8,784 bytes)
105. Topband: Inverted Ground Plane (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Wed, 25 Sep 2002 13:53:50 -0400; The wave does not become a full wavelength tall, and certainly does not need to become that tall to propagate efficiently. Visualize the waves from a pebble hitting a pool of water. The period of th; /archives//html/Topband/2002-09/msg00183.html (9,479 bytes)
106. Topband: Bi-directional prop (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Thu, 26 Sep 2002 16:09:39 -0400; I've been wondering how to test path direction differences for years. The only way I can think of testing path direction differences is to have systems with calibrated signal level voltage meters an; /archives//html/Topband/2002-09/msg00190.html (7,938 bytes)
107. Topband: Bi-directional prop (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 27 Sep 2002 07:38:58 -0400; If the effective radiated power, background noise, and operator's ability to hear signals are different at each end of the path... there is no possible way we can expect equal copy at both ends. Bac; /archives//html/Topband/2002-09/msg00196.html (8,226 bytes)
108. Topband: DU9/N0NM Today (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Sun, 29 Sep 2002 06:30:02 -0400; Jon has to be very strong in order for him to hear me Dave. (One way skip, hi hi) Jon has very high noise for receiving, but he certainly sticks with it morning after morning. I often hear the VK's; /archives//html/Topband/2002-09/msg00211.html (6,808 bytes)
109. Topband: Collins R390 and 75A4 on 160m (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Sun, 4 Aug 2002 16:30:44 -0400; I have both early and late R390's (the late is a 390A). That does not make me an expert, but at least I have looked carefully at the two units. Neither is all that good for BDR or IM3DR, and both ar; /archives//html/Topband/2002-08/msg00019.html (8,447 bytes)
110. Topband: Silent Feedline for RX antennas (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Mon, 26 Aug 2002 07:20:16 -0400; Actually using fully balanced line won't fix any problem, the problems will remain and likely increase significantly. The problem with our antennas and feedlines are that they are never completely p; /archives//html/Topband/2002-08/msg00091.html (10,191 bytes)
111. Topband: Silent Feedline for RX antennas (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 27 Aug 2002 08:56:25 -0400; Good advice Gary, but moving the preamp will not affect the system unless the feedline loss is so high the noise floor is established by the preamp and not the antenna. By far the most common proble; /archives//html/Topband/2002-08/msg00098.html (8,993 bytes)
112. Topband: Re: Topband: Shielded, Balanced Flag (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 27 Aug 2002 09:12:07 -0400; I think the misconception is that we often mistakenly think the wire inside the "shield" remains the "antenna", and the "shield" magically makes the antenna isolated from surroundings. What actually; /archives//html/Topband/2002-08/msg00099.html (8,218 bytes)
113. Topband: Shielded, Balanced Flag (score: 1): Author: w8ji@contesting.com (Tom Rauch); Date: Tue, 27 Aug 2002 09:20:02 -0400; I don't understand why we would want to shield an antenna. By definition, we can't shield an antenna for "bad signals" like noise or it won't hear any "good signals" like DX. Noise from undesired or; /archives//html/Topband/2002-08/msg00101.html (7,420 bytes)
114. Topband: chicken wire ground screen (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Sat, 31 Aug 2002 10:15:06 -0400; The comprehensive RCA funded study's conclusion was that adding a screen does nothing for efficiency if the installation has even a modest radial ground system. You can find measured comparisons in; /archives//html/Topband/2002-08/msg00121.html (9,317 bytes)
115. Topband: Diversity receiving (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Mon, 1 Jul 2002 20:39:41 -0400; I replied to Ford direct, but since people have a general interest in this.... Just from my experience here, since I have been trying this for a few years now. Polarization diversity has been largely; /archives//html/Topband/2002-07/msg00004.html (8,500 bytes)
116. Topband: Diversity Reception on 160 (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Tue, 2 Jul 2002 23:35:16 -0400; That's an excellent understanding and description of the problem Don. I'm not sure how that would be satisfied using two separate VCO's that are "dial locked", as happens in the FT1000 when one VFO; /archives//html/Topband/2002-07/msg00018.html (9,532 bytes)
117. Topband: Switching in Extra Antenna Length (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 5 Jul 2002 07:49:05 -0400; If you insist on using a trap, avoid a coaxial cable trap. They are easy to build, but are also very lossy on the frequency where they are resonant compared to almost any other trap style. That is b; /archives//html/Topband/2002-07/msg00038.html (9,100 bytes)
118. Topband: Diversity Reception on 160 (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 5 Jul 2002 07:49:04 -0400; The question must not have been worded correctly, because Scott answered everything but the phase question. For everything but AM reception the question is...."Do the receivers share the same local; /archives//html/Topband/2002-07/msg00039.html (8,784 bytes)
119. Fw: Topband: Rules of 2002 South Pacific 160 contest (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 12 Jul 2002 09:25:43 -0400; That was a rule from the first contest, but was removed for later contests where they split the contest into a CW frequency area and a SSB frequency area when it didn't work so well. The new VK band; /archives//html/Topband/2002-07/msg00067.html (7,384 bytes)
120. Topband: W1WCR Beverage book (score: 1): Author: W8JI@contesting.com (Tom Rauch); Date: Fri, 12 Jul 2002 20:58:57 -0400; That certainly would not help anything, and could even make things worse. Think of a K9AY loop, or a Pennant antenna. They act like two closespaced verticals even through they have sloped wires. Bot; /archives//html/Topband/2002-07/msg00072.html (9,101 bytes)

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