Look at this waveform from an AO-85 recording:
https://i.imgur.com/LNW4EP3.png
Every peak is a fade. They repeat approximately every 8 seconds through the entire pass. It seems to me this is due to tumbling. Depending on where you are you may not hear it. I assume the TX antenna is on the side of the sat opposite to you during the fade. Sometimes you get unlucky and you have to live with it. It's not a polarity switch due to the ionosphere.
Here is the audio recording that waveform is from:
https://www.dropbox.com/s/sfw0v9m01gnmipl/2017-07-09_-_2105_UTC_-_AO-85_KG4A...
73, John Brier KG4AKV
On Thu, Apr 11, 2019 at 2:30 PM Jeff Johns via AMSAT-BB amsat-bb@amsat.org wrote:
What is your set-up? I’m just QRP portable and to deal with most fades, it’s just a simple matter to twist my Arrow antenna to keep up with the polarization. AO-91/92 are two of the easiest satellites to work with minimal equipment. Best of luck and 73.
Jeff WE4B
On Apr 11, 2019, at 12:47 PM, James Brown via AMSAT-BB amsat-bb@amsat.org wrote:
Just tried AO92 . The fading seams to be worse then ever! Every time I make a call the responding station gets caught in the fade. is there a way to combat this? I am running CP yagis. Jim _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb