John Papay wrote:

Is anyone copying AO-51 on the far western pass 25July 0009z? I am not hearing it.

73, John K8YSE

Back on now thanks to the heads up from John, and our West Coast command station, WA6FWF. Nothing to worry about on the satellite, it was a result of me trying to adjust the power on the previous pass.

73, Drew

Alan Cresswell wrote:

Hi drew,

I notice that when AO-51 comes over ZL/VK after coming out of eclipse (about 5 minutes since eclipse) that after some use the transponder drops out and will not retrigger for 10 to 15 seconds. This behavior continues right through to LOS. I presume this is caused by the batteries still being only lightly re-charged and with use they drop below some cut-off level. My question is to whether this is of concern and should usage in this part of the world be restricted for longer after eclipse.

73 Alan ZL2BX

Your presumption is correct. The power management software watches both eclipse state from the panel voltages, and battery voltages. Things are currently arranged so that eclipse or battery voltage below a VERY conservative set point reduces downlink power to zero. A similar thing happens when a command station turns 435.150 on along with the regular downlink. As the battery sags, or the spacecraft turns and panel outputs fluctuate sometimes both transmitters will shut off for a few seconds. Of course when this happens the battery quickly rebounds and they pop back on.

Thanks for asking, but it is perfectly fine to continue use when this happens. Especially with the case of ZL, there is plenty of open ocean with no use for things to finish charging up.

73, Drew KO4MA