[Towertalk] TH-7 boom to 40 meter rotatable dipole

[K4BEV@aol.com]

Several of y'all had asked me to keep you informed on my TH-7 boom conversion 
project.
Kirk, K4RO, had modified his tribander with an Omega match per N4KG's design 
and reports not only fine results, but even better, higher contest scores on 
40 meters. With Kirk's encouragement I set off to duplicate this antenna. I 
have a crank-up tower, so could not tune the antenna at it's operating 
height. Tuning it with the tower cranked down proved pointless. The resonant 
frequency changed drastically when extending the tower. I've finally found a 
solution to the problem which not only lets me tune the antenna to 1:1 
anywhere on 40 with the tower extended, it also gives me a 1:1 match on 30 as 
a bonus.
My description of the antenna, with photos, can be found at:
www.k4ro.net/tcg/k4bev_boom/k4bevboom.html

Also: If you haven't checked out K4RO's fine Tennessee Contest Group web site 
it's at:
www.k4ro.net/tcg.html

GL es 73,
Don - K4BEV