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Total 1585 documents matching your query.

201. Re: Topband: Finding AM radio stations for antenna optimizing (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 26 Nov 2007 18:22:24 -0800
For US stations, use http://www.fcc.gov/mb/audio/amq.html Plug in your lat/lon coordinates, a range of frequencies, and a desired distance, and you'll get a text screen full of stations listing power
/archives//html/Topband/2007-11/msg00212.html (8,616 bytes)

202. [TowerTalk] Capacitor to Tune 160M Vertical (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 27 Nov 2007 12:31:32 -0800
Crew, I'm thinking of following N6LF's advice on a rebuild of my 160 vertical by tuning it low and adding series capacitance to tune out the resistance to match it to 50 ohms. I also hope to make it
/archives//html/Topband/2007-11/msg00220.html (7,394 bytes)

203. Re: [TowerTalk] Capacitors To Tune 160 Vertical (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 29 Nov 2007 11:55:55 -0800
Thanks for the many excellent thoughts on this issue. Based on the contents of my junkbox, I began with two .0047 400V dipped micas in series, and pumped 1 kW through them for a few minutes. They got
/archives//html/Topband/2007-11/msg00258.html (8,166 bytes)

204. Re: Topband: beverage dc ground resistance (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Sun, 02 Dec 2007 16:23:16 -0800
Earth is pretty lossy most places. An ohmeter measuring the series circuit that includes earth and my 600 ft Beverage read about 20K ohms before adding the termination. They're in a dense redwood for
/archives//html/Topband/2007-12/msg00014.html (7,476 bytes)

205. Re: Topband: 160m Contest Robot Update (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 03 Dec 2007 14:23:26 -0800
Another issue I ran into with N1MM -- it's programmed to believe that N8SS is N8S, last year's DXpedition. It would not allow me to log it until I changed the call to N8S. I then edited to contact to
/archives//html/Topband/2007-12/msg00026.html (7,608 bytes)

206. Re: [CQ-Contest] Topband: 160m Contest Robot Update (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 05 Dec 2007 14:18:16 -0800
N1MM counted it as a DX country and a 5-pointer. N2IC emailed me to observe that the cause of my problem was an out of date country file. I still see that as a bug, whatever the exact cause. Jim ____
/archives//html/Topband/2007-12/msg00060.html (8,163 bytes)

207. Re: Topband: bandpass filters (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 06 Dec 2007 09:27:57 -0800
Here are my measured data for four ICE filters. Used HP generator and spectrum analyzer. These data are at least 3 years old. All but one of the BCB filters were hamfest purchases. http://audiosystem
/archives//html/Topband/2007-12/msg00070.html (7,831 bytes)

208. Re: Topband: WHAT IS THE BEST (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Fri, 07 Dec 2007 08:32:34 -0800
All of the Tentec high power tuners work well on 160. I have two 229B's and two 238A's. The only downside of these older versions are their dial cords, which are a PITA as they age. I think I heard t
/archives//html/Topband/2007-12/msg00078.html (7,571 bytes)

209. Re: Topband: Peru report....and how to make fireworks withan inverted L (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 11 Dec 2007 00:08:34 -0800
My wire dipoles are hung up about 120 ft in giant redwoods. For nearly a year, one end of the 160 dipole was in contact with branches of the tree that supported it. The wire was #12 THHN. It worked f
/archives//html/Topband/2007-12/msg00097.html (8,946 bytes)

210. Re: Topband: Vertical array (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 13 Dec 2007 09:05:51 -0800
YES, YES, YES! It is VERY instructive to build an NEC model of a simple antenna like a vertical, then add the feedlines to other antennas around it, and study the resulting pattern. I did that, and s
/archives//html/Topband/2007-12/msg00109.html (8,519 bytes)

211. Re: Topband: 400 Ft. RG6 (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Fri, 14 Dec 2007 15:03:06 -0800
No, it is certainly not too long. Coax has very low loss at the frequencies where we use Beverages. Not to make up loss in the coax, but maybe to match levels with your transmit antenna to make switc
/archives//html/Topband/2007-12/msg00119.html (7,491 bytes)

212. Re: Topband: Antenna Noise canceller (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Tue, 18 Dec 2007 15:00:03 -0800
The biggest con is that it is a NASTY key click generator. Problem is in the detection circuit that samples transmitted RF to control switching from transmit to receive. I learned the hard way -- goo
/archives//html/Topband/2007-12/msg00137.html (7,223 bytes)

213. Topband: PA0HIP/DU7 (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 19 Dec 2007 08:04:22 -0800
Willem, PA0HIP, is now QRV in DU7 for a long stay (9 months each year). He's called me twice now on 80M around 1530-1630Z (my sunrise is about 1500Z). He runs 100w with an IC746 into a 160M dipole. H
/archives//html/Topband/2007-12/msg00143.html (6,823 bytes)

214. Re: Topband: 1/8 wave vertical (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 24 Dec 2007 19:18:45 -0800
The taller the antenna, the better it will work (up to at least 1/4 wave). Top loading can make a short antenna more closely approach the performance of a quarter wave. Think of it this way, Bob. It'
/archives//html/Topband/2007-12/msg00179.html (8,685 bytes)

215. Re: Topband: Unusual condx Sunday night on west coast (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 24 Dec 2007 19:25:27 -0800
Yes. I regularly work LP from the Bay Area to EU in the morning on 40M. Signals are ALWAYS stronger on my high dipole than on my Beverages. On 160, it's often a toss-up as to whether the vertical, th
/archives//html/Topband/2007-12/msg00180.html (8,269 bytes)

216. Re: Topband: success with the inverted L (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 26 Dec 2007 08:27:22 -0800
FWIW, 12 turns of coax through an FT240-61 core is a LOUSY choke on 160 (in fact, it's a lousy choke on most bands). A MUCH better choke for 160 would use the #31 cores we bought in a group purchase
/archives//html/Topband/2007-12/msg00191.html (7,424 bytes)

217. Re: Topband: 1/8 wave vertical (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Thu, 27 Dec 2007 07:45:04 -0800
WRONG! WRONG! WRONG! Mistatement of reality. It depends completely on the conditions under which the 1 dB change is made. A 1 dB change in the total loudness of sound IS about what most listeners ca
/archives//html/Topband/2007-12/msg00199.html (8,610 bytes)

218. Re: Topband: Why not add power class to SP TBDC exchange? (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 31 Dec 2007 09:01:13 -0800
I STRONGLY support the addition of an indicator in the exchange for power level. To me, one of the most important benefits of contesting is studying propagation. Having the power level would be a big
/archives//html/Topband/2007-12/msg00255.html (8,270 bytes)

219. Re: Topband: daylight QSOs during the SP (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 31 Dec 2007 09:24:26 -0800
ARRL 160 begins at 2pm local on the west coast, 3 hours before sunset. In that first hour this year, I worked a bunch of guys in EWA, WWA, and BC (700-800 miles) and three in CO (800-1,000 miles) wit
/archives//html/Topband/2007-12/msg00257.html (7,834 bytes)

220. Re: Topband: Daylight QSO's during the SP (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Wed, 02 Jan 2008 08:27:02 -0800
And N6RO is using switchable directional arrays on 80 and 160 that are significantly off-axis when he's working west! Don't know if my station is good enough, but I'd be interested. I also work at ho
/archives//html/Topband/2008-01/msg00017.html (7,832 bytes)


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