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381. Re: Topband: T-loaded vertical (score: 1)
Author: donovanf@starpower.net
Date: Wed, 19 Feb 2020 14:13:20 -0500 (EST)
Hi Ed, The affect of the T-vertical on a nearby HF Yagi is easily modeled in EZNEC or your favorite antenna modelling program. You'll be surprised by the results if the horizontal top is +/- 15% of r
/archives//html/Topband/2020-02/msg00179.html (11,740 bytes)

382. Re: Topband: T-loaded vertical (score: 1)
Author: donovanf@starpower.net
Date: Wed, 19 Feb 2020 14:57:04 -0500 (EST)
Hi Ed, A T-top at right angles to a Yagi will have little affect, but anything close to broadside is very bad within 500 feet or less on 40 meters. Fortunately a 60 foot top is just short enough to h
/archives//html/Topband/2020-02/msg00181.html (13,788 bytes)

383. Re: Topband: 160m activity and propagation (score: 1)
Author: donovanf@starpower.net
Date: Thu, 20 Feb 2020 15:13:16 -0500 (EST)
There is a many, many Russians on 160 meter FT8... -- Original Message -- Greeting all, This season has been interesting not because of highlights but because of a noticeable change in propagation at
/archives//html/Topband/2020-02/msg00198.html (8,858 bytes)

384. Re: Topband: T Top Verticals and yagis (score: 1)
Author: donovanf@starpower.net
Date: Thu, 27 Feb 2020 23:23:23 -0500 (EST)
Hi Ed, Your conclusions based on your modelling are completely consistent with my practical experience and modelling. The most likely degradation is a T-top between 60 and 75 feet long degrading the
/archives//html/Topband/2020-02/msg00247.html (8,218 bytes)

385. Re: Topband: T Top Verticals and yagis (score: 1)
Author: donovanf@starpower.net
Date: Fri, 28 Feb 2020 15:00:28 -0500 (EST)
Hi Paul, If you model -- or build -- a 40 meter Yagi with a nearby T-top vertical with a 60-75 foot top, you'll discover that when the 40 meter Yagi is turned so that its elements are parallel -- or
/archives//html/Topband/2020-02/msg00258.html (11,062 bytes)

386. Re: Topband: T Top Verticals and yagis (score: 1)
Author: donovanf@starpower.net
Date: Fri, 28 Feb 2020 17:08:09 -0500 (EST)
Hi Paul, A little modelling will answer the question more completely and accurately than I can answer it in writing. I was referring to the case where a 40 meter Yagi is on one tower and a T-vertical
/archives//html/Topband/2020-02/msg00262.html (13,492 bytes)

387. Re: Topband: 9 circle RX array combiner board (score: 1)
Author: donovanf@starpower.net
Date: Sun, 1 Mar 2020 19:30:44 -0500 (EST)
There's no shortage of 2N5109s on eBay for about one dollar each www.ebay.com/sch/i.html?_from=R40&_nkw=2n5109&_sacat=0&_sop=15 73 Frank W3LPL -- Original Message -- Hi Rick, Yes, the 2N5109s are alm
/archives//html/Topband/2020-03/msg00008.html (11,004 bytes)

388. Re: Topband: 9 circle RX array combiner board (score: 1)
Author: donovanf@starpower.net
Date: Sun, 1 Mar 2020 19:51:57 -0500 (EST)
One advantage of using Ebay is their excellent refund policies if you get cheated. I've used it many times and never suffered a loss. But you have only two weeks to file a claim. 73 Frank W3LPL -- Or
/archives//html/Topband/2020-03/msg00011.html (8,768 bytes)

389. Re: Topband: Phasing lines (score: 1)
Author: donovanf@starpower.net
Date: Tue, 3 Mar 2020 16:23:30 -0500 (EST)
My experience with LDF4-50 and LDF4-75 is exact;y the same as Peter's. Its always best to use an antenna analyzer or TDR to cut all of the cables to the same length. Its very, very easy to do. -- Ori
/archives//html/Topband/2020-03/msg00045.html (8,671 bytes)

390. Re: Topband: Inverted L with elevated radials for topband (score: 1)
Author: donovanf@starpower.net
Date: Thu, 5 Mar 2020 23:29:01 -0500 (EST)
"Sooner or later everything old is new again" (Stephen King) February 1922 QST page 30 The 1BCG antenna used for the transatlantic tests was a T cage over a radial counterpoise. The antenna is hung b
/archives//html/Topband/2020-03/msg00069.html (12,543 bytes)

391. Re: Topband: Slightly OT - amplifier noise (score: 1)
Author: donovanf@starpower.net
Date: Sat, 14 Mar 2020 23:43:34 -0400 (EDT)
Hi Rick, A noise receiving antenna close to a noise source is used in conjunction with a higher performance receiving antenna such as a Beverage or an array of short verticals and a passive or active
/archives//html/Topband/2020-03/msg00182.html (10,104 bytes)

392. Re: Topband: Miracles again ... (score: 1)
Author: donovanf@starpower.net
Date: Fri, 20 Mar 2020 00:53:39 -0400 (EDT)
W2MF also mysteriously disappeared... -- Original Message -- OK1RD disappeared from first place : http://www.arrl.org/system/dxcc/view/DXCC-160M-20200319-USLetter.pdf He voluntarily refused to be a l
/archives//html/Topband/2020-03/msg00255.html (7,494 bytes)

393. Re: Topband: Ground Conductivity (score: 1)
Author: donovanf@starpower.net
Date: Tue, 24 Mar 2020 00:05:58 -0400 (EDT)
Excellent skin depth reference here: www.antennasbyn6lf.com/files/ground_skin_depth_and_wavelength.pdf Ground characteristics are much more significant for vertical polarization than for horizontal p
/archives//html/Topband/2020-03/msg00303.html (9,753 bytes)

394. Re: Topband: DXCC Committe (score: 1)
Author: donovanf@starpower.net
Date: Tue, 24 Mar 2020 00:08:11 -0400 (EDT)
N2MF also vanished from the 160 meter DXCC listings... -- Original Message -- I don't wish to drag this debate out any longer than necessary, but some credit is due the League and the DXCC desk. I wa
/archives//html/Topband/2020-03/msg00304.html (9,385 bytes)

395. Re: Topband: DXCC Committe (score: 1)
Author: donovanf@starpower.net
Date: Tue, 24 Mar 2020 00:43:03 -0400 (EDT)
oops... It was W2MF who vanished from 160 meter DXCC A few weeks ago he was #296 Apologies to Brian N2MF #255 73 Frank W3LPL -- Original Message -- From: donovanf@starpower.net To: Topband@contesting
/archives//html/Topband/2020-03/msg00305.html (9,388 bytes)

396. Re: Topband: Feedline Grounding and Feedline Chokes (score: 1)
Author: donovanf@starpower.net
Date: Wed, 25 Mar 2020 22:44:59 -0400 (EDT)
Hi Bob, Bonding (not grounding...) coax to the bottom of a tower helps to divert lightning currents from the coax shield to the ground system at the base of the tower Bonding coax to the top of the t
/archives//html/Topband/2020-03/msg00339.html (8,220 bytes)

397. Re: Topband: RG-6 Delay cables (score: 1)
Author: donovanf@starpower.net
Date: Wed, 8 Apr 2020 21:28:23 -0400 (EDT)
RG-17 has the same problem, but the Type LC connector (a giant F connector) solved the migration problem the same way the F connector does. 73 Frank W3LPL -- Original Message -- Very astute. You may
/archives//html/Topband/2020-04/msg00042.html (8,812 bytes)

398. Re: Topband: BCB Filter Recommendation? (score: 1)
Author: donovanf@starpower.net
Date: Thu, 16 Apr 2020 15:06:37 -0400 (EDT)
Hi Ed, What is the frequency of your local BCB transmitter? This is the best brickwall filter -- capable of handling 200 watts -- that money can buy. Its provides at least 40 dB of attenuation below
/archives//html/Topband/2020-04/msg00060.html (8,461 bytes)

399. Re: Topband: BCB Filter Recommendation? (score: 1)
Author: donovanf@starpower.net
Date: Thu, 16 Apr 2020 18:16:36 -0400 (EDT)
Ed, If your receive loop has a preamp at its feed point, its very likely that the preamp is being overloaded by the nearby BCB station. If that's the case, a filter after the preamp will not help. 73
/archives//html/Topband/2020-04/msg00068.html (11,749 bytes)

400. Topband: Topband Contester W3YOZ / W3SO Silent Key (score: 1)
Author: donovanf@starpower.net
Date: Thu, 16 Apr 2020 19:43:04 -0400 (EDT)
It is with great sadness that I write this message. It has come to my attention that Marty Johnson W3YOZ has become a silent key as of 4-14-2020 I will post more information as it becomes available.
/archives//html/Topband/2020-04/msg00070.html (6,613 bytes)


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