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301. Topband: ZL3REX (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Fri, 23 Mar 2001 11:22:56 -0500
N5RG: Rex was ZL2REX, but his prefix was changed a few years ago to more accurately reflect the fact he lives on the South Island. Any ZL2REX address is good. Rex is a good example of ingenuity and p
/archives//html/Topband/2001-03/msg00122.html (7,280 bytes)

302. Topband: superdirectivity (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Sun, 25 Mar 2001 07:21:55 -0500
It's not my assertion, it is a well-established fact echoed by many. It also applies to any receiving system, no matter what the frequency unless the system is limited by INTERNAL noise. For example
/archives//html/Topband/2001-03/msg00133.html (11,474 bytes)

303. Topband: WPX (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Mon, 26 Mar 2001 09:56:34 -0500
Hi Bob, The band was active and there were good signals from Europe. Unfortunately, as in most SSB contests, many US operators with poor receiving conditions (they couldn't even hear the locals calli
/archives//html/Topband/2001-03/msg00138.html (7,397 bytes)

304. Topband: modeling question (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Mon, 26 Mar 2001 09:56:34 -0500
Hi Pete, You are probably asking for problems if you have a yagi anywhere near the top of the tower with insulated elements. The insulation will be subjected to very high voltages under all types of
/archives//html/Topband/2001-03/msg00139.html (8,096 bytes)

305. Topband: modeling question (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Mon, 26 Mar 2001 22:01:00 -0500
You'll see in my example at the end the statement above is a wild guess without any meaning. You were very lucky it worked Larry. Voltage goes up only by the square root of the power increase. If yo
/archives//html/Topband/2001-03/msg00145.html (9,483 bytes)

306. Topband: modeling question (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Tue, 27 Mar 2001 07:21:12 -0500
My point is the voltage varies all over the place with the electrical characteristics of the structure. Power can NOT be used to quantify the problem. (100 watts might be excessive power in some cas
/archives//html/Topband/2001-03/msg00148.html (8,560 bytes)

307. Topband: Yagi on RF excited towers (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Thu, 29 Mar 2001 12:59:57 -0500
It is impossible to give one answer about common-mode impedance of a baluns. It would only be a wild guess without knowing the type of balun and many other things. I tested a Hygain BN-4000 two days
/archives//html/Topband/2001-03/msg00157.html (8,580 bytes)

308. Topband: Re: [MFSK] Suggested Frequencies for MFSK operation (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Thu, 1 Feb 2001 08:43:27 -0500
Hi Murray, I'm copying this to two 160 reflectors because this impacts 160 meter operators and they deserve to know what is going on. Anyone on those reflectors this discussion is on the MFSK reflect
/archives//html/Topband/2001-02/msg00000.html (10,765 bytes)

309. Topband: Loopsticks on 160 (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Wed, 28 Feb 2001 10:03:05 -0500
There are a lot of wive's tales about Litz wire, one being that the parallel wires increase surface area. Factually, the exact opposite happens. For a given conductor diameter Litz wire increases wi
/archives//html/Topband/2001-02/msg00106.html (9,723 bytes)

310. Topband: MFSK on 160m (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Tue, 2 Jan 2001 06:19:20 -0500
As a point of general information, we now have several stations using MFSK on 1838 and lower. MFSK sounds like musical tones, and is a few kHz wide. One guy tonight had his gain too high, and had ton
/archives//html/Topband/2001-01/msg00016.html (8,106 bytes)

311. Topband: "Too Long Beverages"/SP Contest (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Tue, 2 Jan 2001 06:38:21 -0500
Hi Bill, You need to do more than look at the pattern, and users of large arrays need to know something else is going on other than "pattern". At my QTH, I can look very clearly at phase shift with w
/archives//html/Topband/2001-01/msg00017.html (8,917 bytes)

312. Topband: Question abt gain in bi- vs uni-directional Beverage (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Fri, 5 Jan 2001 00:37:52 -0500
Hi Fritz, Gain absolutely is meaningless in this application. We can parallel two Beverages a small distance apart, sum the outputs, gain 3 dB, and signal to noise will remain exactly the same! The r
/archives//html/Topband/2001-01/msg00031.html (9,470 bytes)

313. Topband: 2 Wire Beverage Question (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Fri, 5 Jan 2001 21:41:07 -0500
I don't find that much difference Jeff. 73, Tom W8JI w8ji@contesting.com -- FAQ on WWW: http://www.contesting.com/FAQ/topband Submissions: topband@contesting.com Administrative requests: topband-REQ
/archives//html/Topband/2001-01/msg00042.html (6,712 bytes)

314. Topband: Question abt gain in bi- vs uni-directional Beverage (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Fri, 5 Jan 2001 21:41:07 -0500
In addition to what Gary said, you can add loading inductors periodically along the antenna. The Zo of the antenna increases (requiring a termination higher than 1000 ohms generally) and the pattern
/archives//html/Topband/2001-01/msg00043.html (9,055 bytes)

315. Topband: What is this! (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Fri, 5 Jan 2001 21:41:07 -0500
Hi Bill, The "band noise" from the north has been very high lately. The noise I hear is propagated noise, because I am in a rural area and my antennas are a long distance from noise sources. Sometime
/archives//html/Topband/2001-01/msg00044.html (7,929 bytes)

316. Sv: Topband: Question abt gain in bi- vs uni-directional Beverage (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Sat, 6 Jan 2001 15:00:21 -0500
Hi Henrik, Measuring Vp is very difficult. The easiest way to determine the optimum inductance is with a modelling program like Eznec that allows you to insert loads. Otherwise, the process is long.
/archives//html/Topband/2001-01/msg00058.html (9,918 bytes)

317. Topband: 160 Meter Propagation (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Sat, 6 Jan 2001 15:00:21 -0500
What I always worry about is the noise level on the other end. A receiver in the middle of city like Singapore won't have the same noise floor as one in a rural area. The difference can be 20 dB or
/archives//html/Topband/2001-01/msg00059.html (9,384 bytes)

318. Topband: 160 Meter Propagation (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Sat, 6 Jan 2001 15:27:46 -0500
Hi Bob and all, It's well established the average noise level near the Equator is much higher than noise at higher latitudes. It's also well-established the even quiet urban locations are many dB noi
/archives//html/Topband/2001-01/msg00061.html (9,256 bytes)

319. Topband: JA path today (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Sun, 7 Jan 2001 07:57:28 -0500
The JA path was open southwest today even at sunrise, although a separate path did appear NW (normal direction) right at sunrise. The SW path was the clearer and more stable. Nil signals west. SW hap
/archives//html/Topband/2001-01/msg00072.html (7,012 bytes)

320. Topband: 160 Meter Propagation (score: 1)
Author: w8ji@contesting.com (Tom Rauch)
Date: Sun, 7 Jan 2001 08:17:20 -0500
Hi Greg, I can't imagine the weather having anything to do with it, except as it affects noise level. I find the same thing about the A and K index. Many of the days with what should be good numbers
/archives//html/Topband/2001-01/msg00073.html (9,319 bytes)


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