Using the keps from this morning (epoch 13333.066), I measured the frequency of the telemetry signal of AO-73 during a 43 deg pass at about 1648 UTC (Nov 29). This is a pass with the satellite in the sun The frequencies are the frequency “at the satellite” calculated by SatPC32 to place the center of the telemetry in the middle of my 3.0 kHz USB passband. Thus the frequency of the center “at the satellite” are 1.50 kHz higher than these. Elevation xx where the frequency is 145935.xx MHz 0 .94 5 .87 10 .81 15 .73 20 .70 25 .62 30 .60 35 .56 40 .57 43 .54 40 .48 35 .42 30 .37 25 .39 20 .36 15 .32 10 .30 5 .27 0 .20

Thus a change of about 600 Hz over the entire pass with the frequency DECREASING. ---------------------------------------------------------------------------------------------- Using the keps from this evening (epoch 13333.744), I measured the frequency of the telemetry signal of AO-73 during a 21 deg pass at about 0340 UTC (Nov 30). This is a pass with the satellite in shadow, running on batteries. The frequencies are the frequency “at the satellite” calculated by SatPC32 to place the center of the telemetry in the middle of my 3.0 kHz USB passband. Thus the frequency of the center “at the satellite” are 1.50 kHz higher than these. Elevation xx where the frequency is 145934.xx MHz 0 145933.98 5 .00 10 .12 15 .16 **** 20 .21 **** 20 .32 **** 15 .48 **** 10 .50 5 .65 2.5 .74 0 .76 Thus a change of about 800 Hz over the entire pass with the frequency INCREASING. However, where noted with ****, there were were sudden shifts in frequency up and down of 1.0 to 1.5 kHz. During this pass, the linear transponder was on, and I assume the sudden shifts of frequency noted by **** could have been caused by changes in total power used by the transponder. --------------------------------------------------------------------------------------------- The first pass above was during battery charging and the frequency decreased. The second pass was during battery discharging and the frequency was increasing. The sudden shifts of frequency are very obvious when you are in QSO on the transponder. It would be interesting for someone to correlate the frequency shifts with some parameter such as voltage or temperature. Ron W5RKN EM10ci