What is the TO-108 uplink frequency?

TO-108 listens on 435.270-435.290 MHz (USB linear inverting).

What is the TO-108 downlink frequency?

TO-108 transmits on 145.915-145.935 MHz (USB linear inverting), 145.910 MHz (CW) and 145.890 MHz (GMSK 4k8).

When does TO-108 pass over my location?

Open TO-108 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.

TO-108 (TIANYAN 01): Frequencies, Status & Passes

Next passes over your station

Pass times depend on where you are. Track TO-108 on the live map to see its next passes over your station.

TO-108 frequencies

Uplink	Downlink	Beacon	Mode
435.270-435.290 MHz	145.915-145.935 MHz	—	USB linear inverting
—	145.910 MHz	—	CW
—	145.890 MHz	—	GMSK 4k8

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 TO-108

TO-108 (CAS-6) is the amateur radio payload of Tianqin-1, a Chinese technology satellite for the country's gravitational-wave astronomy programme. The 35 kg satellite was built by DFH Satellite Co. for Sun Yat-sen University and the Huazhong University of Science and Technology, and launched on 20 December 2019 on a Long March 4B rocket from Taiyuan. CAMSAT supplied the amateur payload: a CW beacon, GMSK telemetry and a 20 kHz wide U/v linear transponder, first switched on in June 2020 under the callsign BJ1SO.

The transponder is inverting: uplink 435.270–435.290 MHz, downlink 145.935–145.915 MHz. Use LSB up and USB down. Because the uplink is on 70 cm, most of the Doppler shift is on your transmit side.

AMSAT's page for TO-108, updated in April 2025, says the transponder works only intermittently, about two seconds on and five seconds off, which makes normal SSB contacts very difficult. AMSAT's linear satellite summary of March 2026 still described it this way and said the beacons were sending only a carrier. Check recent AMSAT reports before trying it.

Status

Listed as working, but nobody reported hearing TO-108 on AMSAT in the last 30 days.

From reports filed on AMSAT, last 30 days.

Orbit

Type	Low Earth orbit
Altitude	598–619 km
Inclination	97.7°
Period	96.9 min
TLE epoch	2026-10-09 19:22 UTC

Orbital elements: CelesTrak, checked every 3 hours.

Questions about TO-108

What is the TO-108 uplink frequency?: TO-108 listens on 435.270-435.290 MHz (USB linear inverting).
What is the TO-108 downlink frequency?: TO-108 transmits on 145.915-145.935 MHz (USB linear inverting), 145.910 MHz (CW) and 145.890 MHz (GMSK 4k8).
Is TO-108 active?: Listed as working, but nobody reported hearing TO-108 on AMSAT in the last 30 days.
When does TO-108 pass over my location?: Open TO-108 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.

TO-108