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121. RE: [TowerTalk] Lighting (score: 1)
Author: "David Robbins K1TTT" <k1ttt@arrl.net>
Date: Tue, 6 Jul 2004 12:53:03 -0000
Its definitely a myth. Grounding does not prevent strikes, though it may stop you from getting damage from strikes so you don't know you ever had them. Also the statistics of the geographic distribut
/archives//html/Towertalk/2004-07/msg00185.html (11,618 bytes)

122. RE: [TowerTalk] Lighting (score: 1)
Author: "David Robbins K1TTT" <k1ttt@arrl.net>
Date: Wed, 7 Jul 2004 20:57:11 -0000
Unfortunately the physics of arcs across large gaps is much different than that of sparks across small gaps. The small gap between your finger and the doorknob breaks down in a single avalanche once
/archives//html/Towertalk/2004-07/msg00284.html (20,970 bytes)

123. RE: [TowerTalk] Limitation on tower width. Was: RevocationofBuildingPermit? (score: 1)
Author: "David Robbins K1TTT" <k1ttt@arrl.net>
Date: Sat, 17 Jul 2004 17:56:39 -0000
You guys are obviously living in the wrong places. My town is just going through rewrite of zoning bylaws... right up front in the section on 'wireless communicating facilities' it completely exempts
/archives//html/Towertalk/2004-07/msg00479.html (12,648 bytes)

124. RE: [TowerTalk] Limitation on tower width. Was: RevocationofBuildingPermit? (score: 1)
Author: "David Robbins K1TTT" <k1ttt@arrl.net>
Date: Sun, 18 Jul 2004 11:34:02 -0000
I'm an engineer and keep myself very happy since I don't have an xyl to worry about... but this area is the summer home of the boston symphony, has plenty of skiing in the winter, lots of fresh air,
/archives//html/Towertalk/2004-07/msg00498.html (14,746 bytes)

125. RE: [TowerTalk] (no subject) (score: 1)
Author: "David Robbins K1TTT" <k1ttt@arrl.net>
Date: Sun, 18 Jul 2004 16:02:23 -0000
Repeat after me.. google is our friend... I had my doubts on this one, but sometimes it is amazing what you find on there... just searched for "100vdc motor"... only 895 hits. Lots for motor controll
/archives//html/Towertalk/2004-07/msg00500.html (9,553 bytes)

126. RE: [TowerTalk] Replying to the list...AGAIN! (score: 1)
Author: "David Robbins K1TTT" <k1ttt@arrl.net>
Date: Wed, 21 Jul 2004 21:25:50 -0000
It sure seems to me that everyone who wants to reply to the list has figured out how to do it. And undoubtedly many replies have gone back to message originators also... and still the thread continue
/archives//html/Towertalk/2004-07/msg00574.html (10,026 bytes)

127. RE: [TowerTalk] Taller tower, shorter mast or vice versa? (score: 1)
Author: "David Robbins K1TTT" <k1ttt@arrl.net>
Date: Wed, 21 Jul 2004 22:56:12 -0000
20' of mast out the top of a tower is not only a big strain on the mast, but also on the top of the tower. Be sure that the tower, bearing, and rotor combination can handle what you want to put up th
/archives//html/Towertalk/2004-07/msg00581.html (10,210 bytes)

128. RE: [TowerTalk] Hole Digging Question (score: 1)
Author: "David Robbins K1TTT" <k1ttt@arrl.net>
Date: Thu, 22 Jul 2004 21:37:32 -0000
he had the right idea. Topsoil has a lot of air and water in it from all the critters that dig holes as they go about daily life and plant roots. If you dig your hole bigger than needed and use form
/archives//html/Towertalk/2004-07/msg00657.html (9,155 bytes)

129. RE: [TowerTalk] Lightning Strikes Map (score: 1)
Author: "David Robbins K1TTT" <k1ttt@arrl.net>
Date: Wed, 28 Jul 2004 22:03:31 -0000
The intellicast data as well as all the other lightning maps you may see in the u.s. and Canada (and now many other countries as well) come from Vaisala. See their stateside map at: http://www.lightn
/archives//html/Towertalk/2004-07/msg00857.html (9,927 bytes)

130. Re: [TowerTalk] Positive and Negative Lightning Strikes (score: 1)
Author: k1ttt@arrl.net
Date: Thu, 29 Jul 2004 07:03:02 -0400 (EDT)
by definition a 'negative' stroke is where the cloud is negatively charged and the ground is positively charged. a 'positive' stroke has negative charge on the ground and positive in the cloud. to co
/archives//html/Towertalk/2004-07/msg00893.html (8,891 bytes)

131. Re: [TowerTalk] spider balls (score: 1)
Author: k1ttt@arrl.net
Date: Thu, 29 Jul 2004 07:26:07 -0400 (EDT)
sorry i don't have time right now to get lots of details, but here are some references that anyone working in the lightning protection industry should be familiar with. CIGRE "Guide to procedures for
/archives//html/Towertalk/2004-07/msg00894.html (10,350 bytes)

132. RE: [TowerTalk] Grounding, Lightning & corona discharge (score: 1)
Author: "David Robbins K1TTT" <k1ttt@arrl.net>
Date: Thu, 29 Jul 2004 20:43:42 -0000
Lightning is a complex waveform. Typical rise times can be 1-2 microseconds with tails that decay from 10 to 100's of microseconds. A sine wave with a 1 microsecond rise time (1/4 of the cycle) would
/archives//html/Towertalk/2004-07/msg00930.html (13,383 bytes)

133. RE: [TowerTalk] Lightning Energy (score: 1)
Author: "David Robbins K1TTT" <k1ttt@arrl.net>
Date: Fri, 30 Jul 2004 20:33:00 -0000
8 that storm. It cloud the and the way those happen is like this... normally charges separate in the cloud so the negative charge is at the bottom and the positive at the top. The negative charge at
/archives//html/Towertalk/2004-07/msg00999.html (9,923 bytes)

134. RE: [TowerTalk] Rohn Torque Bar confusion (score: 1)
Author: "David Robbins K1TTT" <k1ttt@arrl.net>
Date: Tue, 3 Aug 2004 19:51:28 -0000
plane, then of of degrees scheme tower is guy but the farther away the attachment point is from the center of rotation the bigger the angle on the guy wire so the higher the resistance to the twist.
/archives//html/Towertalk/2004-08/msg00059.html (9,469 bytes)

135. RE: [TowerTalk] Rohn Torque Bar confusion (score: 1)
Author: "David Robbins K1TTT" <k1ttt@arrl.net>
Date: Tue, 3 Aug 2004 22:41:53 -0000
There is no argument that a 6 point guy is far superior to a 3 point with or without torque arms. Just look at the original geometry, the torque arms can obviously not do anything until they are turn
/archives//html/Towertalk/2004-08/msg00066.html (15,371 bytes)

136. Re: [TowerTalk] Rohn Torque Bar confusion (score: 1)
Author: k1ttt@arrl.net
Date: Wed, 4 Aug 2004 06:38:56 -0400 (EDT)
the increased stretch is just the first step. now figure the change in angle of the deflection of the guy wire and calculate the force vector at the end of that torque arm vs the force it would be on
/archives//html/Towertalk/2004-08/msg00079.html (15,041 bytes)

137. Re: [TowerTalk] Tram Line Material (score: 1)
Author: k1ttt@arrl.net
Date: Tue, 17 Aug 2004 06:46:04 -0400 (EDT)
i use 1/4" ehs with big grips. this gives plenty of strength and the big grips let the pulley riding the wire go all the way to the top without clamps getting in the way. ____________________________
/archives//html/Towertalk/2004-08/msg00324.html (9,662 bytes)

138. RE: [TowerTalk] antenna height vs hassle (score: 1)
Author: "David Robbins K1TTT" <k1ttt@arrl.net>
Date: Mon, 23 Aug 2004 10:54:17 -0000
Don't forget to ask the concrete company if they have a wheelbarrow crew. Many of them will have labor available to manually move concrete if pumping or other powered methods aren't possible. David R
/archives//html/Towertalk/2004-08/msg00436.html (11,472 bytes)

139. RE: [TowerTalk] snow static, Quad v. Yagi (score: 1)
Author: "David Robbins K1TTT" <k1ttt@arrl.net>
Date: Wed, 1 Sep 2004 00:12:08 -0000
Of course the gradient is real, and very measurable... even in clear air. Even with no storm around there is a gradient that can be easily measured and a current constantly flowing from the ground th
/archives//html/Towertalk/2004-08/msg00705.html (14,304 bytes)

140. Re: [TowerTalk] Why Rain static is worse on the top antenna. (score: 1)
Author: k1ttt@arrl.net
Date: Thu, 2 Sep 2004 06:43:46 -0400 (EDT)
i hate to throw a monkey wrench in your arguments... but this one is not correct. the noise can start well before the rain or snow start, and indeed can happen when there is no rain or snow at all i
/archives//html/Towertalk/2004-09/msg00036.html (8,611 bytes)


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