[TowerTalk] Flex-Weave

[Jim Brown]

On 6/25/2018 7:53 PM, Gary wrote:
> As I have watched the club's wire antennas fail from being rolled and unrolled through the years. I would like to hear of people's experiences with flex-weave. It looks like a good solution for an antenna that spends most of its time rolled up.

I fell for it, and ordered lengths of #14 and #12. Every antenna built 
using it was on the ground after only a year or two. NOT recommended.

A better idea might be carefully looking at construction of the antennas 
and avoid the weak spots. Most ends, including feedpoints, are potential 
weak points. Several things I've learned the hard way.

1) Avoid hard bends. We use egg insulators, fold the wire back, and 
apply two U-clamps. The insulator is the electrical end of the antenna, 
and if the wire is cut long, length can be tweaked by loosening and 
re-clamped. At feedpoints, we run the wire over thimbles, fold the wire 
back on itself, and make electrical connections to the center insulator 
using copper split-bolt connectors.

2) Avoid solder -- soldered connections are likely to CAUSE mechanical 
failure.

3) Solid THHN #12 or even #14 is a great choice for portable antennas. 
Solid is recommended over stranded because there's far less corrosion.

4) Carefully roll up antennas just as you transmission lines. Form a 
loop of the loose end, tape it, then roll it up and tape it again. Done 
right, this avoids kinks that stress the wire, and makes it easy to 
unroll them next time. Also, when applying the tape, fold the free end 
back on itself to make it easy to peel.

5) Choose feedpoint insulators with great care. The Budwig HQ-1 works 
pretty well IF you don't count on it for mechanical support. Run both 
wires through an egg insulator above it, clamp the wires and fold them 
back to the connection points, using split bolts for the electrical 
connection. Done this way, the egg insulators (both ends and center) 
carry the mechanical stress. The length of that folded wire DOES count 
as part of the antenna.

73, Jim K9YC