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Re: Contacts on AO-10

Of further interest on this thread, after listening to the transponder and beacon for the last couple of nights I have noticed the following:

1) Immediately prior to a fade, the AO-10 transponder (and the beacon) will first drop in frequency by 30-40 Hz, then drop off rapidly as the power runs out.  The first and the second drops occur over the space of two or three seconds.
2) When the fade ends the transponder and beacon frequencies quickly stabilize at their original positions.
3) The received signal strength is very steady until the frequency drops and returns to its pre-fade level as soon as the power comes back on.
4) These observations were the same at near perigee and to about half way out (at my LOS)

The interesting part about all this is that I could not detect deep fading of the received signal other than that associated with the loss of power when the sun falls on the end of the spacecraft.  Given the above, the satellite must be using the *omni* antennas rather than the high gain antennas as was previously believed.  If the high gain antennas were in use there should be much more deep and regular fading of the signal as the satellite rolls/tumbles on its axis.

John - VE8EV

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