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[TowerTalk] mobile hf antenna loading coil

To: <towertalk@contesting.com>
Subject: [TowerTalk] mobile hf antenna loading coil
From: n1lo@hotmail.com (Mark .)
Date: Tue, 20 Feb 2001 12:54:07 -0500
Greetings gang!

Welcome back, TowerTalk!

A big thank you to George, K0FF, for the tip to use nylon grommet strips for 
winding inductor coils. These things are great! After finally obtaining some 
in the largest size, and some 14 gauge bare copper, I was able to make a 
beautiful new air-core loading coil for my mobile HF antenna.
I wound the coil by placing the strips (serrations/teeth turned out) on a 
piece of 3" PVC, taping them temporarily in place, and winding the wire 
around them. After filling the grommet strips with hot melt glue to secure 
the coils, I slipped the works off of the pipe yielding a coil of 
approxiately 3.75" diameter, with about 7.5 turns per inch. The turn spacing 
is very close to 1 wire diameter with 14 gauge wire.

  I have completed a construction plan for my mobile antenna that has 
illustrations for a better description of the coil winding process:
http://www.qsl/net/n1lo/antenna.htm


Here is some data on the grommet strips and where to buy:
0.323? X 0.23? X 12.5? nylon serrated grommet strips, manufactured by 
Catamount, part number GSNY-192-9
A pkg of 25 for about $10 is available from McMaster-Carr as catalog 
#85085K8
(they have a fabulous on-line store at http://www.mcmaster.com)

In making the lightweight capacity hat for the mobile antenna, I used 
stainless steel spring wire and found some great materials for soldering 
stainless steel and chrome:
Kester #66 acid flux silver solder (96% tin, 4% silver), (1 lb roll
McMaster-Carr #7791A22) and LA-CO flux paste #22404, (4oz jar McMaster-Carr 
#7696A2)

Happy Building!

--...MARK_N1LO...--
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