> PS - With work, I was able to model tower-mounted antennas > for 10M, using two-element colinears for both transmit and > receive, that achieved 70 dB isolation at 400' vertical > spacing. When I improved the model of the tower to account > for other hardware, guy wires, etc., not so much. It might be > a useful application on 6M.
I've seen a 10m single-site repeater work (100 kHz split) with 300 feet of vertical separaton between antennas (single half-wave dipoles). The Tx was a Micor with tube amplifier running 1/3 kW, Rx was a Maxtrac. No additional filtering. No desense. I was suprised to see it work, and wouldn't have believed it unless I saw it. Of course, the site noise floor may have been elevated a bit which would have masked some desense... Glad we're all on the same page now :-) --- Jeff WN3A