Byron:
My comments embedded below.
73 de
Gene Smar AD3F
----- Original Message -----
From: "Byron Tatum" <bjtatum@ev1.net>
To: <TowerTalk@contesting.com>
Sent: Friday, August 06, 2004 9:18 PM
Subject: [TowerTalk] Cadweld One-Shots
Hello-
I have {1} a report concerning the Cadweld "One-Shots" and a {2}
question regarding attaching solid ground wire to tower legs.
1. ...Everything was assembled as shown in instruction sheet, however
most of the molten metal blew out of the bottom of the fixture. ....
Same thing happened to my first One-shot attempt. I used similar material -
electrician's putty - to block up the bottom and side holes of the ceramic
mold. I used the putty that G&B make and is found in Home Despot's
electrical department (right next to the 500-foot rolls of #14 house wire.
;o) ) However, instead of putting a blob of the material around the opening,
I rolled a thin snake of it in my hands and carefully molded it against the
bottom and side holes and onto the ground rod or wire itself. Maybe that
was the step that allowed my shots to work without subsequent blowouts.
2. I have the #2 solid wire, one up to each tower leg. What would be the
best long-term method of connecting each wire to a tower leg { A bolt
junction it right at base area}. With all I read about corrosion, etc. I
want to have it right.
What kind of tower do you have? For my Trylon, with its angle steel legs, I
used three clamps from Harger: model 222-T This is a heavy tinned bronze
clamp that is made to accommodate wire gauges from #2 (what I used) up to
4/0 or thereabouts. You can see a drawing by scrolling down to Section
2.6.1, Bonding Lugs, at http://www.harger.com/productinformation.htm .
This clamp has a bolt hole that is just the right size to be bolted to
Trylon's existing spare holes. I used some spare Trylon hardware (nice
touch, guys!) to fasten the three Harger clamps to the three Trylon legs and
to the #2 ground wires emerging from the buried ground rods.
Someone else will have to answer authoritatively regarding Rohn towers and
their tubular legs. But my guess would be to use a piece of stainless steel
shim wrapped around each (galvanized) leg of the tower, then hold your
ground conductor against it with a pair of stainless steel hose clamps. I
suspect you can't snug up on the clamp too much without crushing the tower
leg (a bad thing.)
With either solution, don't connect to the tower leg right above the
concrete. You'll create a nice right-angle, high-inductance connection.
I'd suggest you connect to the tower leg about a foot or more above the
concrete. You'll end up with a fairly large radius on the wire as it leaves
the tower steel on its way into the ground. I'd also suggest running the
last foot or so of your ground wire through a piece of garden hose before it
enters the earth. This will protect it from chafing against the tower base
during lawn mowing, etc.
BTW: Harger also make a nice clamp that bites into the steel if there is no
pre-existing hole to bolt to. (I don't know about you guys, but I'd get a
little hinkey drilling into my tower's structural steel components.) I used
several of these to connect my tower's shunt feed wires to the steel
bracing, and my coax shield ground wires to the tower legs, both at random,
non-drilled, spots on the structure. Click on the same URL above, then
scroll to Section 2.5.10, Parallel Cable Connectors, and look for their
model 213-T.
Thanks, Byron WA5THJ.
You're welcome. AD3F
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
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_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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TowerTalk mailing list
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