I have got an old Cushcraft A4S tribander. It is working on all 3 bands. The low SWR point on 10 and 20 is 1.3:1 but on 15 it is 1.8:1. I had to shorten the driven element from the factory specs by a few inches, apparently because the prior owner had 8" leads extending from a Hy-Gain BN-86 balun, see http://qsl.net/nz5n/Hygain%20balun.jpg
(the BN-86 manual says to keep the leads as short as possible to avoid lowering the frequency). I thought about shortening the leads but the antenna is working quite well as is on 20 and 10 so I decided not to mess with it.
Any thoughts on how to lower the SWR on 15, without messing up 10 and 20? I'm only able to cover a small portion of 15 before the SWR rises above 2:1.
73, Bill NZ5N