[TowerTalk] TH7 conversion

[James Cain]

I'm new to this reflector; never thought I'd have the opportunity to put up a tower again. I'm hoping to get some help here, and thanks in advance. 

I want to turn a TH7 into a TH3 MK4. I compared drawings and parts lists and I need to buy two 10 Meter traps and the TH3 beta match. Then I can build a TH3 per the Hy-Gain plans. No problem there. 

My concern is that by using TH7 element parts I may end up with a "TH3" that is not to spec in terms of element size and taper. And there may be other issues I haven't thought of. 

I can no longer do heavy antenna work on the tower, so I am stuck having someone else put the beam up for me. It has to be "set and forget." It would be a real hassle to try to strap the homebrew TH3 on the tower at, say, 20 feet, and fiddle with it. To put the antenna up and find that it's resonant out of one or more bands would be a disaster, to say the least. I have experience with trapped tribanders ("Suckermasters") and I know how unforgiving they can be; screw up 10 Meters and you screw up 15 and 20 as well, etc. 

I would love to hear from anybody who has experience in this area. Thanks,

Jim Cain, K1TN
7 miles east of Mountain, Wisconsin