[Antennas] Best guess on adjusting a 80 down to 75

[Ray Brown]

  Greetings, all.. I bought and tossed up a 80 / 40 dipole in my back yard,
in a NVIS fashion, so that I can work stations within a couple hundred miles.
The problem is that the measured SWR on both antennas are at the top of
the CW band, and I want to go in the middle of the phone band. My radio
doesn't like greater than 3:1 SWR for some reason.

  Now, I'm not going to cut the copper. Just double it back tight so that it
doesn't cause any arcing or corona. (Only running 100w, but just to be safe.)

  So... all other things being equal, using the best scientific guessing, how much
would I need to move the eggs, the insulators, back to get to the middle of the 
phone bands on this 80 / 40? I'd really like to do this just once if possible.

  Thanks!


                Ray, KB0STN