QB50p2 FM Transponder Tested

QB50p1 and QB50p2 – Image Credit ISIS

AMSAT-Francophone report that the FM transponder on QB50p2 (EO-80) has been tested. A Google English translation of the post on their website reads:

On June 19, 2014, two 2U CubeSats QB50p1 and QB50p2 were launched as part of the QB50 precursor program into a polar orbit at an altitude of 680 km.

The satellite QB50p2 (object 40032) is equipped with a secondary FM transponder payload developed by AMSAT-F.

On Tuesday, June 16, 2015 almost 1 year after launch the AMSAT-F FM transponder on QB50p2 was activated by the main control station in The Netherlands for the duration of an orbit. At the Polytechnique in Palaiseau, we were able to receive telemetry in CW and put into action the FM transponder with an output of 1.5W.

A very strong signal was received at Palaiseau and by F6HCC in Brittany. The transponder was turned off at the end of the orbit.

In a few weeks, the transponder should be activated permanently. The signal is very strong, we will probably use a lower power level of 500 mW or 1 watt. We will inform you later.

QB50p1 (EO-79 / FUNcube-3) is equipped with a linear transponder for SSB and CW. The first tests were successfully completed in April and its transponder should also be enabled full-time in a few weeks.

Gérard – F6FAO

QB50 Amateur Radio Information


The IARU Satellite Frequency Coordination Panel Status pages list these frequencies for the two satellites:

QB50p1 (FUNcube-3) has a VHF 9600 bps BPSK telemetry downlink plus a linear U/V transponder for SSB/CW communications similar to that already flying on FUNcube-1 with an output of 400 mW.
• 145.815 MHz 9600 bps BPSK telemetry beacon
• Inverting SSB/CW linear transponder 400 mW PEP
– 435.035 – 435.065 MHz Uplink LSB
– 145.965 – 145.935 MHz Downlink USB

QB50p2 has  a VHF 9600 bps BPSK telemetry downlink plus a separate RF payload from AMSAT-Francophone which will comprise of a FM voice transponder with UHF uplink and VHF downlink. It can also transmit FX25 telemetry at 9600 bps.
• 145.880 MHz 9600 bps BPSK telemetry beacon
• 145.840 MHz 9600 bps FSK FX25

To use the FM voice transponder Paul Stoetzer N8HM suggests programming these frequencies into your rig’s memories:

EO-80 AOS - TX 435.070 MHz 210.7 Hz CTCSS, RX 145.840 MHz
EO-80 2   - TX 435.075 MHz 210.7 Hz CTCSS, RX 145.840 MHz
EO-80 TCA - TX 435.080 MHz 210.7 Hz CTCSS, RX 145.840 MHz
EO-80 4   - TX 435.085 MHz 210.7 Hz CTCSS, RX 145.840 MHz
EO-80 LOS - TX 435.090 MHz 210.7 Hz CTCSS, RX 145.840 MHz

AOS = Aquisition Of Signal. TCA = Time of Closest Approach. LOS = Loss Of Signal

OSCAR Numbers for QB50p1 and QB50p2 CubeSats