John - I should have mentioned that on my OI 565 - I did have an HP608 on the ANT1 port and a 0.1 uv 14 mhz signal was clearly audible . I suspect the switch isolation is at best only in the order of 60 db or so at 14 mhz. 50 uv to .1 uv is 54 db . 73 de Hank K7HP