[TowerTalk] Wire antenna in trees? (Patrick Greenlee) (Kelly Taylor)

[Jim Brown]

The problem with using ordinary copper wire for antennas where the wire 
is under tension is that it stretches. Mine high dipoles are under about 
100# of tension (up 140 ft, fed with RG11), so every few years, I have 
to let down my 80/40 dipole that's built with #10 THHN stranded and 
circumcise it to keep it on frequency. I've since migrated to using #8 
bare solid copper that I've stretched by tying one end to a tree and the 
other end to the trailer mount of my SUV and pulling slowly until it 
breaks.  The result is close to being hard drawn, roughly AWG #9, and 
about 15% longer. Antennas that I've built with this seem not to 
stretch.  Over the years, W6GJB and I have done this with at least 2,000 
ft of #8.

73, Jim K9YC

On 8/6/2017 10:44 AM, Clay Autery wrote:
> Correct...  THHN is not intended for use as exterior antenna wire, but
> it surely does work well...  I can get it in any color I want and in a
> 2500+ foot spool, et al.