AO-27
EYESAT A · amateur radio satellite, NORAD 22825
Not heard todayAO-27 frequencies
| Uplink | Downlink | Beacon | Mode |
|---|---|---|---|
| 145.850 MHz | 436.795 MHz | — | FM |
| — | — | 436.795 MHz | AFSK 1k2 |
| — | 436.797 MHz | — | GMSK 9k6 |
Nominal frequencies, without Doppler. The live map shifts them for your station during a pass. Frequencies: SatNOGS DB (modified: working amateur transmitters only, in MHz), CC BY-SA 4.0.
About AO-27
AO-27 is the amateur radio payload of EYESAT-1, a satellite built by Interferometrics and launched on 26 September 1993 on an Ariane 4 rocket from Kourou. It is one of the oldest FM repeater satellites, and for many years it was the easiest way to make a satellite contact with a handheld radio, which made it a favourite of new operators in the 1990s and 2000s.
AO-27 is no longer a regular part of the FM satellite fleet. After a computer failure in 2012 its control team restored it with new software in 2020, and since then the repeater has run only in short timed windows of a few minutes per orbit. Check recent reports before trying it.
It uses almost the same frequencies as SO-50: uplink 145.850 MHz and downlink 436.797 MHz, with no CTCSS tone. Because the frequencies are so close, check the live map to see which satellite is above your horizon.
Status
Listed as working, but nobody reported hearing AO-27 on AMSAT in the last 30 days.
From reports filed on AMSAT, last 30 days.
Orbit
| Type | Low Earth orbit |
|---|---|
| Altitude | 782–795 km |
| Inclination | 98.7° |
| Period | 100.6 min |
| TLE epoch | 2026-10-28 14:57 UTC |
Orbital elements: CelesTrak, checked every 3 hours.
Questions about AO-27
- What is the AO-27 uplink frequency?
- AO-27 listens on 145.850 MHz (FM).
- What is the AO-27 downlink frequency?
- AO-27 transmits on 436.795 MHz (FM) and 436.797 MHz (GMSK 9k6).
- What is the AO-27 beacon frequency?
- The beacon is on 436.795 MHz.
- Is AO-27 active?
- Listed as working, but nobody reported hearing AO-27 on AMSAT in the last 30 days.
- When does AO-27 pass over my location?
- Open AO-27 on the live map and enter your Maidenhead locator or use GPS: the tracker lists the passes of the next 24 hours with AOS, maximum elevation and LOS, and shifts the frequencies for Doppler.