I never heard anybody but myself on the AO51 2nd repeater, even after announcing on the congested primary channel that the 2nd channel is completely empty. SatPC32 users with CAT control can switch channels with 3 mouse clicks. Here's the entry for your Doppler.SQF file.
AO-51,435300,145920,FM,FM,Nor,0,0,Voice V/U AO-51,435150,145880,FM,FM,Nor,0,0,Voice V/U
Wayne Estes Oakland, Oregon, USA, CN83ik