[...]But only have a 90' high tower and at the top is the center feed point of my 75 meter double extended zepp.  I simply short the open wire line which runs almost vertically and fed it with allot of inductance in series! I assume the two 150' legs acts as top loading. Ground system is from my broadcast experience where for field intensity surveys 36" wide chicken wire was used with a 100' tower most often and a 250 transmitter.  Eight 50' chicken wire radials produced decent field on the midband channels [1000 kHz or so] to measure from.  Here I am using several 150' radials of chicken wire radials.  I hope to stretch some out to 300' but that's going to be about it at my location.