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Total 1524 documents matching your query.

201. [TowerTalk] terminated vee beam (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Sun, 4 Nov 2001 19:25:05 -0500
You can use a feedline from the outer end back to the feedpoint, and recombine that power with the transmitter power through a phasing system. Then you WILL get 3 dB more gain! I did that on a 160-m
/archives//html/Towertalk/2001-11/msg00084.html (8,743 bytes)

202. [TowerTalk] phased verticals (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Mon, 5 Nov 2001 05:28:49 -0500
Or you can simply switch in a 180 degree transformer, but the coax line is probably easier. You do not need to "current force feed" two elements that are fed in phase, or 180 degrees out of phase be
/archives//html/Towertalk/2001-11/msg00092.html (10,197 bytes)

203. [TowerTalk] phased verticals on 6m HELP!! (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Mon, 5 Nov 2001 11:44:36 -0500
If you short the ends of the 1/2 wl of cable together with a perfect short, you should have what appears as a short across the main transmission line! What that does is form two 1/4 open stubs that
/archives//html/Towertalk/2001-11/msg00100.html (9,102 bytes)

204. [TowerTalk] Amplifier Interface (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Thu, 8 Nov 2001 10:05:37 -0500
I missed the question, but if someone e-mails me I'll try to help. Measuring dc steady-state voltages and currents won't tell you much about life of any relay contact or switch in almost any applicat
/archives//html/Towertalk/2001-11/msg00176.html (10,594 bytes)

205. [TowerTalk] Ballon-held Vertical (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Thu, 8 Nov 2001 21:15:34 -0500
I have a 318 foot insulated tower for 160 meters that I can use as a vertical. It is clearly not as good as my 200 foot tall vertical, except for long distances during the daytime when it might be a
/archives//html/Towertalk/2001-11/msg00206.html (8,601 bytes)

206. [TowerTalk] Feedlines and phasing (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Mon, 12 Nov 2001 08:00:20 -0500
Hi Bob, I assume you are going to fire the antennas in different directions, to fill in a null. If so, that is OK as long as neither antenna has significant radiation in the same desired directions.
/archives//html/Towertalk/2001-11/msg00266.html (8,336 bytes)

207. [TowerTalk] 40m 4square - factors relating to gain (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Mon, 12 Nov 2001 21:38:48 -0500
What I find is when lower in frequency, verticals work much better than models seem to predict. My 160-meter dipole at just over 300 feet just ties a 200-foot vertical in the best directions for the
/archives//html/Towertalk/2001-11/msg00283.html (9,415 bytes)

208. [TowerTalk] 40m 4square - factors relating to gain (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Tue, 13 Nov 2001 09:39:42 -0500
Assuming the model is reliable, that is true for transmitting. I tend to believe that would be true in many cases on 40 meters and above, but not on 80 meters and lower where it seems modelling prog
/archives//html/Towertalk/2001-11/msg00294.html (9,887 bytes)

209. [TowerTalk] 80m Dipole ssb/cw switching (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Wed, 14 Nov 2001 16:32:54 -0500
That statement is clearly incorrect, no matter how many capital letters are in it. The vast majority of any broad banding comes from additional loss, just as the ARRL Handbook and people like Walt M
/archives//html/Towertalk/2001-11/msg00339.html (9,705 bytes)

210. [TowerTalk] 80m Vertical ssb/cw switching (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Wed, 14 Nov 2001 18:59:40 -0500
The ARRL Antenna Handbook describes stub systems that work, but they correctly point out that all stub systems add loss and it takes a complicated system to significantly extend bandwidth without us
/archives//html/Towertalk/2001-11/msg00348.html (8,947 bytes)

211. [TowerTalk] MFJ ARTIFICIAL GROUND (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Thu, 15 Nov 2001 10:30:52 -0500
Let's try this again. The message bounced, and I don't keep copies, and I hate to retype the same thing twice. The MFJ artificial ground can not make a 1/4 wl ground lead grounded at the far end into
/archives//html/Towertalk/2001-11/msg00360.html (9,104 bytes)

212. [TowerTalk] How to mount choke balun? (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Fri, 16 Nov 2001 10:33:28 -0500
How do you keep the boom from being a shorted turn, and reducing inductance of the balun to nearly zero? Any time a conductive slug or ring is placed inside a coil, the counter magnetic forces from
/archives//html/Towertalk/2001-11/msg00381.html (9,951 bytes)

213. [TowerTalk] Equipment grounding - in shack (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Fri, 16 Nov 2001 10:49:15 -0500
As Steve points out, single point grounding is best used at the entrance of the building. The power, telco, CATV, and amateur cables should all be grounded together to a common ground at the entranc
/archives//html/Towertalk/2001-11/msg00383.html (10,304 bytes)

214. [TowerTalk] MFJ ARTIFICIAL GROUND (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Sat, 17 Nov 2001 08:03:08 -0500
Hi Al, Let's leave all the personal attacks for bar fights, and keep it technical here. My point is simple. One of the big common myths in antennas is that a simple inductor in series with a line, or
/archives//html/Towertalk/2001-11/msg00392.html (14,423 bytes)

215. [TowerTalk] Ropes, strings, and swivels. (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Sat, 17 Nov 2001 08:27:31 -0500
In an off-reflector conversation, I mentioned using swivels to prevent ropes and support lines from twisting antennas. It was suggested I post this as general information. I use large saltwater swive
/archives//html/Towertalk/2001-11/msg00393.html (7,553 bytes)

216. [TowerTalk] How to mount choke balun? (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Sat, 17 Nov 2001 11:17:36 -0500
Aluminum is a very effective shield if it is thicker than a few skin depths. Anyway, easy enough to measure something I already have laying around. I just measured what I used as an 80-meter 4" air
/archives//html/Towertalk/2001-11/msg00396.html (10,450 bytes)

217. [TowerTalk] correction MFJ ARTIFICIAL GROUND (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Sat, 17 Nov 2001 18:43:10 -0500
That should have been: A simple series L/C circuit can only change the reactive part of the impedance of the system, it can not change the **resistance** nor can it make a lead "longer" or "shorter"
/archives//html/Towertalk/2001-11/msg00406.html (8,672 bytes)

218. [TowerTalk] Laying out antennas (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Sun, 18 Nov 2001 13:47:37 -0500
Are there any reasonably priced devices for laying out wire antennas or tower and guy lines, so the direction heading is accurate? What I'm interested in is something that uses magnetic north or mayb
/archives//html/Towertalk/2001-11/msg00410.html (8,229 bytes)

219. [TowerTalk] How to mount choke balun? (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Sun, 18 Nov 2001 13:47:37 -0500
Skin depth is pretty thick in most materials at 60 Hz, that why effective shields on low frequencies are generally ferrous materials, to divert the magnetic flux. The amp probably was not designed t
/archives//html/Towertalk/2001-11/msg00411.html (9,956 bytes)

220. [TowerTalk] Laying out antennas (score: 1)
Author: W8JI@contesting.com (Tom Rauch)
Date: Mon, 19 Nov 2001 20:55:48 -0500
Thanks for all the good suggestions, I'm still digesting all the information. It looks like some sort of really good sighting compass would work if I stay away from the barbed wire fences. What I nee
/archives//html/Towertalk/2001-11/msg00419.html (9,968 bytes)


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