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Total 284 documents matching your query.

61. Re: [TowerTalk] Crankup towers-- tiltover (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Sat, 01 Sep 2007 21:07:43 -0400
On my Rohn 45G foldover in Vermont, I fabricated a bracket system which kept the yagi horizontal,while the tower folded over. This allowed full lowering, and prevented skewering the roof when the tow
/archives//html/Towertalk/2007-09/msg00022.html (7,422 bytes)

62. Re: [TowerTalk] name that antenna (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Mon, 03 Sep 2007 10:39:31 -0400
The FAA and other countries aviation agencies still maintains contact with trans-oceanic flights via HF. For the transatlantic traffic, it's Gander NF, and Shannon EI which are the comm centers. They
/archives//html/Towertalk/2007-09/msg00085.html (7,959 bytes)

63. Re: [TowerTalk] Carolina Windom, etc. (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Wed, 05 Sep 2007 23:25:14 -0400
Reid, You asked about the CW80 and your 737, as well as your ic2kl/at500. responses in digest issue 27 were all over the lot. (AB7E's were spot-on, however.) First hand experience: I've had CW160's @
/archives//html/Towertalk/2007-09/msg00208.html (9,272 bytes)

64. Re: [TowerTalk] Carolina Windom (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Thu, 06 Sep 2007 10:50:47 -0400
Guys...let me RESTATE my comments regarding the CW80, before we drag this thread through the fields of speculation: 1) To Reid's initial question: I am presently using a cw80 with an AT500. Works fin
/archives//html/Towertalk/2007-09/msg00220.html (7,852 bytes)

65. [TowerTalk] dangling guy wires (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Thu, 06 Sep 2007 15:15:09 -0400
This is an extension of the 90' tiltover discussion, where the guys were dangling as it went up. Two things to point out: 1) W3GM used a falling derrick method on his 100' 25g's, with 4 way guying. T
/archives//html/Towertalk/2007-09/msg00235.html (7,738 bytes)

66. Re: [TowerTalk] Carolina Windom, etc. (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Fri, 07 Sep 2007 23:09:34 -0400
Well, yes, Gary, that's true. But suppose it's 1.2:1? is that because it's 1.2:1 at the antenna, or because whatever wierd impedance is presented at the feedpoint is transformed to something close to
/archives//html/Towertalk/2007-09/msg00259.html (8,555 bytes)

67. Re: [TowerTalk] Carolina Windom, etc. (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Sun, 09 Sep 2007 11:56:45 -0400
Thanks for the appology, Gary, but it was unnecessary. Maybe even premature. I read it before the TT digest arrived, so it made me curious. Some of what you were reacting to WAS my comment. We seem t
/archives//html/Towertalk/2007-09/msg00284.html (10,573 bytes)

68. [TowerTalk] RG6 (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Tue, 11 Sep 2007 16:26:15 -0400
TT: I'm wondering if anyone has worked with RG6 for power transmission, or might know the limitations. Radio Shack recently added a line of "waterproof" crimp connectors, and a crimping tool for use
/archives//html/Towertalk/2007-09/msg00325.html (7,636 bytes)

69. [TowerTalk] RG6/u (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Tue, 11 Sep 2007 18:08:38 -0400
Thanks, all, for the helpful comments and suggestions. Although I'll be running 500w into a rough-matched condition, it's worth a try to see what breaks. As for the connector question, I'm looking at
/archives//html/Towertalk/2007-09/msg00335.html (7,283 bytes)

70. Re: [TowerTalk] exploding foundations and semantic quibblesregarding Ufer & "Single Point" grounds (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Fri, 14 Sep 2007 07:26:23 -0400
It was written, regarding UFER grounds: "Sinking the ground rod several inches below the bottom of the foundation hole and only running copper wire out the bottom of the concrete is no problem. If ho
/archives//html/Towertalk/2007-09/msg00475.html (8,415 bytes)

71. [TowerTalk] Ufer gnds/foundations (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Fri, 14 Sep 2007 09:49:13 -0400
I'm not a student of Ufer grounds. However, I HAVE engineered some large towers...including a 500' self supporter. Everyting I've read says...provide a low impedance path AROUND the foundation, not t
/archives//html/Towertalk/2007-09/msg00479.html (7,438 bytes)

72. Re: [TowerTalk] exploding concrete (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Sat, 15 Sep 2007 14:21:32 -0400
"The final analysis is that you must not, under any circumstance, permit an electric current to run through the concrete. Even if a good conductor is embedded in the concrete, a lightning strike will
/archives//html/Towertalk/2007-09/msg00526.html (8,175 bytes)

73. Re: [TowerTalk] exploding concrete (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Sat, 15 Sep 2007 15:23:18 -0400
Dave, I dunno. Intuitively, I suppose it makes sense to provide a robust path around the foundation, as well as a static drain for the rebar cage. But I wouldn't want to use the rebar cage as my prim
/archives//html/Towertalk/2007-09/msg00532.html (10,695 bytes)

74. [TowerTalk] commercial towers and lightning (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Thu, 20 Sep 2007 12:54:21 -0400
W6wrt asked about having something ABOVE our yagi, to take the brunt of a strike. On every tower I've seen which was over 190' and therefore required lighting, there has been a lightning rod, to carr
/archives//html/Towertalk/2007-09/msg00651.html (7,602 bytes)

75. [TowerTalk] Reply posting...a request (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Sat, 22 Sep 2007 18:11:29 -0400
C'mon, folks, please do NOT simply reply to a digest post. It repeats the entire digest. I've lost track of who said what to whom about what, at this point. While I'm sure you had something important
/archives//html/Towertalk/2007-09/msg00688.html (6,752 bytes)

76. Re: [TowerTalk] skyhawk, kt36xa opinions (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Tue, 09 Oct 2007 10:38:04 -0400
Getting Steve's tribander report would be worthwhile. First, you're comparing a 24' boom to a 32' boom. But actually, not all of the 24' is being used on each band in the skyhawk. So, you may forfeit
/archives//html/Towertalk/2007-10/msg00195.html (7,114 bytes)

77. [TowerTalk] OCF dipole (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Wed, 31 Oct 2007 08:53:51 -0400
Samir: First, you WILL need a tuner to use an OCF dipole. They have many merits, and some demerits, which you can read on W8JI's site, or in the white paper on the Yankee Clipper Contest Club website
/archives//html/Towertalk/2007-10/msg00877.html (8,088 bytes)

78. Re: [TowerTalk] OCF Dipole (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Wed, 31 Oct 2007 12:33:10 -0400
It is not necessarily true that a tuner will be required, except for on the 15 meter band. I am personally running the Buckmaster OCF dipole, which they claim uses a 6:1 balun of a non-descript type.
/archives//html/Towertalk/2007-10/msg00895.html (8,149 bytes)

79. [TowerTalk] 4 element CFL Phased Array (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Wed, 31 Oct 2007 19:51:58 -0400
So, the question is how to manage the power division when you're driving Hg Fluorescent elements? OK...Steve's right, this is off topic. But I'm not even the least bit apologetic. I'm glad the topic
/archives//html/Towertalk/2007-10/msg00913.html (7,045 bytes)

80. [TowerTalk] Particle Swarm Optimization of LPDA'S (score: 1)
Author: Jim Jarvis <jimjarvis@optonline.net>
Date: Fri, 02 Nov 2007 06:53:15 -0400
Just when you thought you understood antenna modelling.... The August edition of the IEEE Antenna & Propagation Magazine arrived yesterday, having obviously travelled long-path to get here. It contai
/archives//html/Towertalk/2007-11/msg00030.html (7,596 bytes)


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