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Total 152 documents matching your query.

61. Re: [TowerTalk] Was Radials... 160m High angle vs. low angle (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Fri, 16 Jun 2006 18:35:57 +0000
Having a 160m inverted vee with the apex at 60' is like having a 10m inverted vee with the apex at 4'. It's a cloud burner. A 160m dipole at 100' is a LOW antenna. That said, there ARE high angle nig
/archives//html/Towertalk/2006-06/msg00366.html (8,077 bytes)

62. [TowerTalk] mystery low band antenna between Chevrol and Goujon,France (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Thu, 22 Jun 2006 12:43:00 +0000
Eric, what's the height of that tower, again? At first, I thought it might be FR1, the 2MW longwave station on 162KHz. But that's north of you, in Allouis, above Limoge. Have forwarded the URL to two
/archives//html/Towertalk/2006-06/msg00507.html (7,162 bytes)

63. [TowerTalk] FW: antenna (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Thu, 22 Jun 2006 16:06:36 +0000
Eric, If the antenna is just off the E70, then I found it on Google Earth. 44deg 56m 59s North x 0 deg 11m 21s East sound about right? Interesting mystery. While I pour through international allocati
/archives//html/Towertalk/2006-06/msg00513.html (6,625 bytes)

64. [TowerTalk] MW antenna in Bordeaux (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Thu, 22 Jun 2006 17:50:10 +0000
Eric....here's your answer, thanks to F8BPN Hi, I answered directly to Jim on his previous mail, before to read this one. This is France Info tower on 1.206 MHz. Eric, how long do you stay around Bor
/archives//html/Towertalk/2006-06/msg00518.html (8,170 bytes)

65. [TowerTalk] MW antenna in Bordeaux (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Fri, 23 Jun 2006 12:19:39 +0000
Jan's link, http://perso.orange.fr/tvignaud/galerie/am/33bordeaux.htm , appears to be the antenna Eric saw. The buildings look like what I saw in his pics, and on Google Earth. F8BPN identifies it as
/archives//html/Towertalk/2006-06/msg00537.html (8,051 bytes)

66. [TowerTalk] MW antenna in Bordeaux (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Fri, 23 Jun 2006 17:45:45 +0000
Since the tower is series fed with open wire 'coax', and we can't see any feed to the sloping wire, I'm inclined to think that the sloper is a reflector, and is broadened in cross section by the cage
/archives//html/Towertalk/2006-06/msg00546.html (7,562 bytes)

67. [TowerTalk] DO *NOT* WORK ON ANTENNAS During Rain (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Mon, 26 Jun 2006 20:27:27 +0000
Dear TT: The voltage gradient in a broadcast antenna ground field, in the event of a direct strike has been modelled, and confirmed by measurement as 1,000v/m. This was reported in BroadcastEngineeri
/archives//html/Towertalk/2006-06/msg00588.html (7,927 bytes)

68. [TowerTalk] Gap Voyager gotchas (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Fri, 30 Jun 2006 20:25:02 +0000
K5UJ's comments regarding the voyager are right on the money. I owned one...sold it, and bought it back. It works fairly well on 80 an 40. On 160, as Rob said, the 'radials' are extensions of the OCF
/archives//html/Towertalk/2006-06/msg00741.html (7,362 bytes)

69. [TowerTalk] Porcupines and other wives tales (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Tue, 04 Jul 2006 18:59:02 +0000
I had tuned out on the water tower-omni antenna lightning protection, and noticed the "porcupine" post. Things morphed somewhat, I see. To avoid forensic reading and proper attribution, let me say th
/archives//html/Towertalk/2006-07/msg00102.html (9,743 bytes)

70. Re: [TowerTalk] strike variability---sometimes you can't outrun thebear (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Wed, 05 Jul 2006 16:31:23 +0000
While it is true that you don't have to be faster than the bear, just faster than the next guy...sometimes you MAY find a bear intent on chasing things that run. One down, you're next. The variabilit
/archives//html/Towertalk/2006-07/msg00122.html (9,025 bytes)

71. [TowerTalk] cadweld v. silver solder (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Sun, 09 Jul 2006 19:20:48 +0000
AM Broadcast antenna installations routinely use silver solder. Can't say there's never been a problem, but I haven't seen one reported. I can say that I've observed many tens of direct tower strikes
/archives//html/Towertalk/2006-07/msg00282.html (7,784 bytes)

72. [TowerTalk] Ground to ground lightning? I doubt it. (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Tue, 11 Jul 2006 17:59:08 +0000
Tom, Not to be a complete contrarian, but the pic you posted could just as easily be two strikes, cloud to ground, more or less contemporaneous. Seems like a much more plausible explanation of the im
/archives//html/Towertalk/2006-07/msg00341.html (8,707 bytes)

73. [TowerTalk] grounds (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Tue, 11 Jul 2006 18:05:37 +0000
JC, TT: The answer to "how to bond them all together" is to run a peripheral strap around the house, and tie all grounds to that strap, at the point where they're available. Reliance upon internal wa
/archives//html/Towertalk/2006-07/msg00342.html (6,978 bytes)

74. [TowerTalk] second floor shack (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Thu, 13 Jul 2006 17:23:30 +0000
This could be as inflammatory as the lightning topic, and I sense we're getting wrapped around the axle. Having written several white papers on grounding and shielding in instrumentation, and having
/archives//html/Towertalk/2006-07/msg00454.html (12,430 bytes)

75. [TowerTalk] Second Floor Shack--redux (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Thu, 13 Jul 2006 18:19:37 +0000
Regarding single ended or voltage fed antennas, and 'tuned grounds': Unless you are absolutely committed to sitting in the middle of your bloody antenna, and ignoring RF exposure safety requirements,
/archives//html/Towertalk/2006-07/msg00458.html (6,774 bytes)

76. [TowerTalk] Inv Ell Bandwidth (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Fri, 14 Jul 2006 07:32:21 +0000
Here we go again... so which is it? Inverted L's have plenty of bandwidth or Inverted L's little bandwidth??? -0- The answer is... the perceived bandwidth of an Inv. Ell, or a full sized vertical, fo
/archives//html/Towertalk/2006-07/msg00490.html (7,416 bytes)

77. [TowerTalk] (no subject) (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Sat, 15 Jul 2006 20:40:13 +0000
Paul, What I would do is put a thrust bearing where the rotor normally would be located, allowing a mast of 10' or so to extend below it. THEN, I would use thinwall irrigation pipe as a 'torque tube'
/archives//html/Towertalk/2006-07/msg00550.html (8,701 bytes)

78. [TowerTalk] sealing PVC (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Sat, 15 Jul 2006 20:41:03 +0000
Electricians "pug seal" is a clay like material used to plug holes around service entrances and ground wires. Costs 2 bucks at your local hardware store. Goes a long way. It also stays reasonably fle
/archives//html/Towertalk/2006-07/msg00551.html (7,775 bytes)

79. [TowerTalk] ma550 & marb (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Mon, 17 Jul 2006 20:04:43 +0000
TT: I have a friend who is looking for an MA550 w/ marb in good shape on the east coast. He will need to move it to Oswego NY. If you know of one, msg me privately, please. Jim n2ea@arrl.org ________
/archives//html/Towertalk/2006-07/msg00606.html (6,686 bytes)

80. [TowerTalk] Blue Herons, ospreys and other pesky critters (score: 1)
Author: "Jim Jarvis" <jimjarvis@verizon.net>
Date: Mon, 24 Jul 2006 21:00:30 +0000
At our place in MD, the ospreys were pretty settled on the DNR nesting poles in the creek. There were smaller birds that tended to land on convenient places on the sailboat, and crap things up. Dangl
/archives//html/Towertalk/2006-07/msg00730.html (7,995 bytes)


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