Hi John,

I am not sure if you have received any other answer but…

AO73 has been operating in full time 24/7 transponder on mode for some time now.

The telemetry is also transmitted at low power at the same time on the nominal 145.935 MHz.

The nominal transponder frequencies remain unchanged: Uplink: 435.150 – 435.130 MHz LSB (Inverting) Downlink: 145.950 – 145.970 MHz USB

But these do drift a for Hz depending upon the on board temperature – back in the day, perhaps twelve years ago, the design of the oscillators was a compromise between stability and power consumption.

JO97, being a more recent design, does not have this “feature”.

73

Graham G3VZV

From: JOHN GEIGER via AMSAT-BB amsat-bb@amsat.org Sent: Friday, September 13, 2024 7:02 PM To: amsat-bb amsat-bb@amsat.org Subject: [AMSAT-BB] AO-73 question

Great to see that AO-73 has been QRV again. I seem to remember seeing somewhere that it has shifted frequency somewhat from the published frequencies. Is this correct? What are the current uplink and downlink passbands for it?

73 John AF5CC

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