[amsat-bb] Overcoming desense on FO-29

Is the use of a downconverter effective in overcoming desense on the FO-29 70 cm downlink? The downconverter would convert 435 to 10 MHz. Receiver is an SDR. (I have different ones for HF and for VHF.) Also, what is the minimum recommended distance between linearly polarized 2 m and 70 cm antennas on the same crossboom? Does it help with desense if one is mounted horizontally and the other vertically?

Thanks. Jim Barbre KB7YSY