We made the mode change this evening to V/S on AO-51. I and the rest of the command team are a bit concerned that we may not have enough battery capacity now to sustain operation through eclipse in V/S mode. We cannot PTT the transmitter with PL like the UHF transmitters, nor is there any way to lower the downlink power on S. If the battery voltage drops too low, the voltage watchdog will shut the S transmitter off and it will remain off until commanded back on.

If we cannot make it through eclipse in this mode, we can try to use the automatic scheduler to enable the S transmitter at a predicted time upon exiting eclipse each orbit. We've not tried to use the scheduler this way before, so there may be some time required to get things working.This approach will require daily intervention to keep things running.

The next four months are going to be challenging keeping AO-51 as available as possible.

Please either email me directly, or via -bb, or post to http://oscar.dcarr.org/ reception reports for V/S. Send those reports in this week please!

73, Drew KO4MA AMSAT-NA VP Operations