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81. Re: Topband: W1AW inconsistency wd western US (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Fri, 29 Sep 2006 09:12:24 -0700
This is far from universally true. I'm in the Santa Cruz mountains, at the bottom edge of the San Francisco Bay area, a semi-rural and moderately quiet QTH, but I have yet to hear any signals from EU
/archives//html/Topband/2006-09/msg00148.html (7,726 bytes)

82. Re: Topband: Fw: Noise Limiter Help - Thanks (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sun, 01 Oct 2006 08:44:25 -0700
I have no experience (yet) with the MFJ box, but my ANC-4 is a very nasty key-click generator if it is in line with a transceiver. I suspect the carrier detection for the T-R switching. If I am corre
/archives//html/Topband/2006-10/msg00006.html (7,956 bytes)

83. Re: Topband: Fw: Noise Limiter Help - Thanks (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sun, 01 Oct 2006 23:15:29 -0700
Thanks, Martin, and thanks Tom for the detailed response. Now I understand your design logic. 73, Jim _______________________________________________ Topband mailing list Topband@contesting.com http:
/archives//html/Topband/2006-10/msg00009.html (7,457 bytes)

84. Re: Topband: Radials Again (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 02 Oct 2006 14:43:42 -0700
Because this question is a very good one, it is one that has been asked (and answered) over and over again. The best answer I've seen is in the latest ARRL Antenna Book chapter on Grounding, by Rudy
/archives//html/Topband/2006-10/msg00016.html (9,279 bytes)

85. Re: Topband: Radials Again (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 02 Oct 2006 23:17:56 -0700
You got only part of the story. Elevated radials need to be a significant fraction of a quarter-wave above ground to be as effective as a much larger number of on-the-ground radials, and 10 ft is far
/archives//html/Topband/2006-10/msg00020.html (7,895 bytes)

86. Re: Topband: Radial length (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 03 Oct 2006 21:32:06 -0700
Of course not. Long radials do not detract from the performance of shorter ones. Rudy s work simply shows that for a given quantity of wire in the radial system, you get more bang for your buck near
/archives//html/Topband/2006-10/msg00028.html (7,852 bytes)

87. Re: Topband: Tee Verticals (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 19 Oct 2006 20:42:48 -0700
radials. Several thoughts. What I'm using is quite close to yours -- an 80/40 dipole fed with about 70 ft of 72 ohm kW twinlead (long out of production) against 25 radials that are 70 ft long. I thin
/archives//html/Topband/2006-10/msg00132.html (8,573 bytes)

88. Re: Topband: topband: Tee Verticals (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sat, 21 Oct 2006 09:47:31 -0700
Not necessarily. It will depend on how high the dipole is and how it interacts with your terrain. My 80M vertical (quarter wave) is significantly better than my 35 ft high dipole almost anywhere in N
/archives//html/Topband/2006-10/msg00148.html (7,703 bytes)

89. Re: Topband: Dumb radial question (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 25 Oct 2006 20:58:53 -0700
Where are you making your measurement -- in the shack, or at the base of the antenna? When you added radials, you probably reduced the total impedance of the antenna a bit (that is, wire plus radial
/archives//html/Topband/2006-10/msg00172.html (8,368 bytes)

90. Re: Topband: Need Ideas on 160M Antenna (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 07 Nov 2006 12:15:51 -0700
appreciated. I just moved to a similar situation here in CA, but with a lot more space -- I own 8.5 acres of an old-growth redwood forest! I have two suggestions. Do both if you can, under the theory
/archives//html/Topband/2006-11/msg00050.html (11,133 bytes)

91. Re: Topband: Mysterious Noise - Final (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sat, 11 Nov 2006 15:07:15 -0700
Here s a solid step to FIXING the problem once you find it. It works for most 120VAC noise sources that are carried on or radiated by the AC line. This fix is specifically tailored to 160-40 meters,
/archives//html/Topband/2006-11/msg00084.html (8,510 bytes)

92. Topband: Why Is My Vertical Quieter This Morning? (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 13 Nov 2006 08:08:50 -0700
I have two transmitting antennas for 160 -- a horizontal dipole at 100 ft and a top-loaded vertical with 30 radials. Under normal conditions, the dipole is about 6 dB quieter than the vertical, but
/archives//html/Topband/2006-11/msg00088.html (7,521 bytes)

93. Re: Topband: Mysterious Noise - Final (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 13 Nov 2006 23:56:13 -0700
Yes, our group purchase was for 1,800 pieces, and I took 100 of them. The data on my webpage http://audiosystemsgroup.com/publish was measured from a pre-production prototype that Fair Rite sent me.
/archives//html/Topband/2006-11/msg00092.html (7,680 bytes)

94. Re: Topband: Effect of Trees (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sun, 03 Dec 2006 15:09:54 -0800
You might also add 1) The very nice antenna systems of some big 160 stations. Take a look at the links for K9DX and N6RO, for example. 2) It's worth running HFTA on your site. 3) The high noise level
/archives//html/Topband/2006-12/msg00026.html (9,323 bytes)

95. Re: Topband: plasma TV RFI? (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sun, 03 Dec 2006 14:46:12 -0800
See my response to another post on the topic of RFI. Here are the main points. 1) If it IS the TV, SOMETHING connected to it is acting as a 160 meter transmitting antenna and radiating it strongly en
/archives//html/Topband/2006-12/msg00028.html (10,041 bytes)

96. Re: Topband: easy WAS topband? (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 04 Dec 2006 09:42:21 -0800
It certainly isn't easy from the opposite coast either. I managed it, however, both W1OP and me working HARD to complete the exchange for RI at 5am EST, and having N0MJ answer my CQ only an hour or t
/archives//html/Topband/2006-12/msg00050.html (7,567 bytes)

97. Re: Topband: plasma TV RFI? (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 04 Dec 2006 08:53:12 -0800
I'm not as "up" on specific capacitor types as I should be, but I believe that a DC rating of 600V or so should be safe on a 120VAC circuit. The Digikey book lists Metallized Polypropylene Film and M
/archives//html/Topband/2006-12/msg00053.html (7,605 bytes)

98. Re: Topband: plasma TV RFI? (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 04 Dec 2006 23:12:21 -0800
Thanks, Tom. Can you recommend specific types (that is, construction)? Metallized poly film, etc. ? Jim _______________________________________________ Topband mailing list Topband@contesting.com htt
/archives//html/Topband/2006-12/msg00057.html (7,642 bytes)

99. Re: Topband: plasma TV troubleshooting (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 05 Dec 2006 08:49:38 -0800
HUGE MISCONCEPTION! Current flows in loops, and the source of the noise current is the TV, not "earth ground." "EARTH GROUND" will not solve a noise problem -- the purpose of the bond of the filter c
/archives//html/Topband/2006-12/msg00063.html (8,898 bytes)

100. Re: Topband: plasma TV RFI? (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 06 Dec 2006 08:54:56 -0800
Well, sort of. You will find a more realistic version of this analysis in the tutorials and AES paper that are on my website. I call this "threshold effect" for want of something better. That is, the
/archives//html/Topband/2006-12/msg00083.html (10,772 bytes)

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