Hi, Sounds interesting - but PSK-31 and Doppler may be problematic - will this be a linear transponder or... ? Simon Brown, HB9DRV www.ham-radio-deluxe.com ----- Original Message ----- From: "Robert Bruninga" <bruninga at usna.edu> > 2) PSK-31 multi-user SSB uplink on 29 MHz and FM down link on > 145.825