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Total 149 documents matching your query.

121. Topband: RX loop antenna RX protector (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Tue, 8 Jun 2021 10:28:05 -0500
You probably have a preamp on your rx loop. The first thing to do is kill the dc to it on transmit to shut it down. I have an Airspy HF+Discovery SDR which has a fragile front end. To keep tx RF out
/archives//html/Topband/2021-06/msg00023.html (7,872 bytes)

122. Re: Topband: Question on active vertical spacing (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Sat, 7 Aug 2021 04:51:29 -0500
My rx antennas are around 40 to 50 feet separated. I get good peaks and nulls on 160 and the top of the AM broadcast band. 80 m. doesn't work as well. But 160 is where you really want it to work. Tha
/archives//html/Topband/2021-08/msg00016.html (7,334 bytes)

123. Re: Topband: Inv L corner insulator (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Sun, 26 Sep 2021 04:57:50 -0500
My hunch is that your problem is the wire you are using. My inv. L is strung with hard drawn 7 strand bare AWG 14 copper. Multi-strand or solid soft drawn will probably break on you eventually. 73 Ro
/archives//html/Topband/2021-09/msg00080.html (6,637 bytes)

124. Re: Topband: Anyone using a NCC-1 with 2 magnetic RX loops? (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Sun, 17 Oct 2021 04:46:28 -0500
I have a NCC-1 with a pair of rotatable pixel loops. I have one filter in the NCC-1, a high pass broadcast band filter. It really hits the stations around 1000 and below. Doesn't have much attenuatio
/archives//html/Topband/2021-10/msg00037.html (7,005 bytes)

125. Re: Topband: Balloon Supported Vertical (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Tue, 9 Nov 2021 10:13:00 -0600
I'd look into some kind of drone for this. Rob K5UJ _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
/archives//html/Topband/2021-11/msg00041.html (7,994 bytes)

126. Re: Topband: cheap radial wire? (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Tue, 9 Nov 2021 10:21:19 -0600
Bad idea, except maybe for field day or some other temporary setup due to rust. Also, long thin runs of steel may not return RF well. For permanence it's a lot better to invest in 3000 feet copper t
/archives//html/Topband/2021-11/msg00042.html (8,039 bytes)

127. Topband: Horrendous Local Noise (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Sun, 14 Nov 2021 17:25:06 -0600
spent a while in the shack listening to the noise, and monitoring it on their equipment connected to my Top Band dipole. After about 45 minutes they both went out in the street, and an hour later th
/archives//html/Topband/2021-11/msg00071.html (8,485 bytes)

128. Re: Topband: Need antenna help (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Wed, 8 Dec 2021 05:38:49 -0600
The problem with adding a top wire to your 43 foot vertical is that it is probably not made to support a wire pulling on it at the top, unless it's cross section is uniform and it is guyed at the mid
/archives//html/Topband/2021-12/msg00021.html (7,868 bytes)

129. Re: Topband: Radials on ground (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Sat, 8 Jan 2022 08:02:25 -0600
For medium wave, every ham who transmits with a base excited vertical radiator should get a copy of _Radio-Electronic Transmission Fundamentals_ by B. Whitfield Griffith, Jr. 2nd ed., Noble Pub. Co.,
/archives//html/Topband/2022-01/msg00052.html (7,688 bytes)

130. Re: Topband: Radials on ground v FCP (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Sat, 8 Jan 2022 12:14:26 -0600
I can't comment on the folded counterpoise because I am not familiar with it. The "broadcast model" which I take to mean 120 radials is used because in the case of a 90 degree tower on medium wave, t
/archives//html/Topband/2022-01/msg00056.html (9,627 bytes)

131. Re: Topband: F connector how-to video (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Fri, 4 Feb 2022 17:32:55 -0600
I know many will disagree but I wish the ham industry had never gone to RG6 and F plugs and jacks for filters, preamps and various rx antennas etc. I know that UHF/BNC/N take up more space and cost m
/archives//html/Topband/2022-02/msg00045.html (8,864 bytes)

132. Re: Topband: TV coax + F-connectors (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Mon, 21 Feb 2022 05:28:50 -0600
Good luck with that voltage breakdown rating for foam RG6 running high power through it and other than a flat line. As to the milliwatt loss on transmit, okay FB but on rx with microvolts, I'm alread
/archives//html/Topband/2022-02/msg00099.html (7,479 bytes)

133. Topband: What antenna would you build? (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Thu, 24 Mar 2022 05:18:43 -0500
Good question. I don't think you mentioned any cost limit. Given that I would put up a substantial self supporting commercial tower ~ 130' tall. Solid legs, 5 or 6' face tapering to 1 or 2 feet. Pyro
/archives//html/Topband/2022-03/msg00041.html (7,576 bytes)

134. Re: Topband: Skirted vertical antennas for MF broadcast (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Thu, 7 Apr 2022 05:07:34 -0500
What makes you think it is just being discovered? Rob K5UJ _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
/archives//html/Topband/2022-04/msg00013.html (7,523 bytes)

135. Re: Topband: How good is good enough (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Sat, 12 Nov 2022 17:49:44 -0600
If that were all I could add, I'd switch them to 40 35' radials. The R component of my inverted L on around 1840 is 11 ohms. X is around 20. That's with 101 radials. I look for a R of at least 15 oh
/archives//html/Topband/2022-11/msg00052.html (7,893 bytes)

136. Re: Topband: AM broadcast multiplexing (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Sat, 22 Apr 2023 12:02:42 -0500
I am always amazed at the hams who will buy a home within sight of a broadcast tower. Rule no. 1 when looking for a new QTH is to find where all the AM and FM plants are and avoid them; especially QR
/archives//html/Topband/2023-04/msg00037.html (8,176 bytes)

137. Re: Topband: Topband cw - bugs rhythm, swing (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Sun, 2 Jul 2023 05:37:48 -0500
There were a few electronic key designs that surfaced in the '50s, maybe even late '40s, usually appearing in QST. But then Jim Ricks W9TO designed his TO Keyer which Halicrafters started manufacturi
/archives//html/Topband/2023-07/msg00004.html (8,102 bytes)

138. Re: Topband: Digiwave feedline (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Fri, 11 Aug 2023 06:12:57 -0500
Does this mean we are better off using something like RG8X with copper shield and center conductor for lines to low band rx antennas? 73 Rob K5UJ _________________ Searchable Archives: http://www.co
/archives//html/Topband/2023-08/msg00024.html (6,756 bytes)

139. Re: Topband: Digiwave feedline (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Fri, 11 Aug 2023 13:04:15 -0500
Okay thanks for the explanation. Rob K5UJ _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
/archives//html/Topband/2023-08/msg00025.html (7,275 bytes)

140. Topband: ICE Model 135B Preamp (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Wed, 8 Nov 2023 06:12:07 -0600
On those ICE preamps, check the small dipped inductors, because they can blow open if the preamp is exposed to a high enough RF field. If your preamp is on a rx antenna and you are transmitting with
/archives//html/Topband/2023-11/msg00042.html (6,634 bytes)


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