Roy,
Thanks for the audio. In the weeks since this QRM came to light, with the help of recordings from users, we have found the club whose repeater audio is being retransmitted over AO-92. I do not believe this to be intentional. Despite the coincidence of frequencies involved, I also do not believe it to be a third harmonic. The audio is too clear, the signal is too strong, and repeaters have too much filtering for that to be happening.
I reached out to the board of directors and the repeater trustees, sent links to the audio including callsigns and their net ID. I explained that based on experience that this was likely someone crossbanding into their repeater with a poor choice of UHF frequency, and we could use their help in finding the QRM source, and my goal was to educate and remove it, not point fingers and place blame. The responses ranged from virtual shrugs, to claims of atmospheric conditions, to "there must be something wrong on the satellite end." A few suggested going to the repeater site and listening on UHF while the repeater is active, which is a pretty good idea. Supposedly they would make announcements about it on their nets.
I haven't given up on getting the club to help us find the QRM, but we may need some more convincing. I'll send the new recordings and ask again. Meanwhile, Is there anyone in the Gloucester, MA area that would like to do a little foxhunting for AMSAT?
73, Drew KO4MA AMSAT VP Operations
-----Original Message----- From: AMSAT-BB amsat-bb-bounces@amsat.org On Behalf Of Roy Dean via AMSAT-BB Sent: Thursday, May 21, 2020 12:12 PM To: amsat-bb@amsat.org Subject: Re: [amsat-bb] Terrible Repeater QRM on AO-92 at 15:40z
Yes, terrible QRM during this pass. Have recording as well but no call signs from repeater chatter. Cal / N3CAL
--Roy K3RLD _______________________________________________ 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