I will soon be going up with a Hy-Gain TH3. This 3 element beam is now 17
feet above the ground on the side of the tower. Just put it there to check
the SWR. The beam has directions for either low,mid or the high end of the
band. I have is set for the mid position. As of now the SWR curve for all
three bands are lower than the lowest frequency swr chart shows. Can I
expect the SWR curve to go higher in frequency as I go from 17 feet to the
final height of about 58 feet ?

I am using a current balun (beads on the coax type) the Wire Man sells if
this makes any differance.