I've been tracking AO-109 with my IC-910H and having trouble locating the beacon within the linear transponder's passband. According to the frequency plan, the beacon should be at 435.650 MHz, but I'm only hearing noise at that frequency during passes with good elevation.

Has anyone else successfully copied the AO-109 beacon recently? My setup includes a 17-element 70cm Yagi with good preamp, so signal strength shouldn't be the issue.

Also wondering if the transponder is truly inverting - the documentation shows U/V mode but I want to confirm the sideband relationship before attempting any contacts.

The AO-109 beacon has been intermittent lately. I logged it successfully at 435.651 MHz (not exactly on the published frequency) during a 78-degree pass last weekend. Try listening around ±5 kHz from the published beacon frequency.

Can confirm it's an inverting transponder - transmit LSB on the uplink around 145.875 MHz and listen USB on 435.675 MHz for your own signal. The beacon drift seems related to thermal cycling as the satellite enters/exits eclipse.

I've been using SatPC32 with my G-5500 rotator and it automatically compensates for the Doppler shift on both uplink and downlink. Much easier than manual tracking, especially for beginners trying to find themselves on the transponder passband.