AO-91 (RadFxSat)
NORAD 43017 Semi-Active (daylight only) FM Voice Repeater
Frequencies
| Purpose | Frequency | Mode |
|---|---|---|
| Uplink | 435.250 MHz | FM (67.0 Hz CTCSS) |
| Downlink | 145.960 MHz | FM |
About AO-91 (RadFxSat)
AO-91 (RadFxSat) is an AMSAT FM transponder satellite. It operates as a U/V repeater — uplink on 70cm, downlink on 2m (the reverse of SO-50). The transponder only activates when the satellite is in sunlight, so nighttime passes are silent.
Operator AMSAT
Altitude ~450 km
Inclination 51.6°
Period ~93 minutes
How to Work AO-91 (RadFxSat)
Transmit on 435.250 MHz with a 67.0 Hz CTCSS tone. Listen on 145.960 MHz. Because the downlink is on 2 meters, Doppler correction is minimal on receive. Apply Doppler correction to your 70cm uplink frequency. The satellite is only active during sunlit passes.
Tips
- - Only active during sunlit passes — check if the pass is in daylight
- - Doppler correction matters more on the 70cm uplink than the 2m downlink
- - Lower orbit means shorter but stronger passes
- - Use 67.0 Hz CTCSS tone on uplink
Next 24 Hours — Pass Predictions
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