I just got on EO-79 here. ~ 08:55 EST. I found my downlink after setting my uplink +12 kHz from published spec.

Downlink seemed OK - maybe a bit weak. Significant fading. This was a fairly low pass for me.

Unfortunately, nobody else on the transponder.

Mike

On 12/21/2015 5:16 AM, Wouter Weggelaar wrote:

Hi All,

Today, 21st of December 2015 at 1038 UTC, it is planned that the EO-79 transponder will be turned on for a prolonged period.

The FUNcube transponder subsystem on QB50p1 (EO-79) had been provided by AMSAT-UK and AMSAT-NL and is a similar subsystem as on FUNcube-1, but without the telemetry downlink circuitry.

The current software running on EO-79 does experience occasional reboots. When these reboots happen, the transponder is automatically turned off and will have to be turned back on by a command station. The FUNcube team has selected a few command stations to do so, but be advised the transponder may be off.

TLEs: AMSAT keps name: EO-79 Celestrak keps Name: QB50P1 Celestrak file: cubesat.txt NORAD # 40025 COSPAR designator 2014-033-R

Frequencies: *Uplink:* 435.035-435.065 MHz LSB *Downlink:* 145.935-145.965 MHz USB

EO-79 has been set to only beacon the normal AX.25 beacon every 30 seconds instead of 10 seconds. The beacon frequency is 145.815MHz and consists of AX.25 frames on BPSK. more details about the downlink can be found on the ISIS HAM page at http://isispace.nl/HAM/qb50p.html

We kindly request you to share your experiences with the BB so everyone can benefit from operating tips and tricks, as well as being up-to-date on the status. We would also welcome any observation related to the transponder behaviour when the AX.25 beacon comes on.

Just like FUNcube-1, the crystal oscillator circuits exhibit drift with temperature. This means manual tuning will probably work best.

Lastly, the commanding team will not be available over Christmas, so the current activations are planned from today until Thursday 24th and from Monday 28th until Thursday 31st

73 and have FUN Happy Holidays

Wouter Weggelaar, PA3WEG AMSAT-NL AMSAT-UK _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb

Hi All,

Just as a reminder, we will start our second activation today, Monday 28th until Thursday 31st.

The first activation has shown us that the uplink frequency seems to be off by +12kHz, so please adjust your uplink frequencies accordingly. We are also seeing that activating the transponder makes the satellite power negative, meaning the solar arrays can not generate enough power to keep the transponder running permanently. This is not unexpected as the satellite is operating in a different mode than originally anticipated during the design phase.

We are discussing various ways to solve this, including multiple ways of scheduling the transponder operations. With these discussions ongoing we would still like to try the second activation and obtain some more data about the system. We will activate the transponder for as much time as the power budget allows, but please be aware that you may find the transponder to be off while the batteries recharge.

TLEs:

AMSAT keps name: EO-79 Celestrak keps Name: QB50P1 Celestrak file: cubesat.txt NORAD # 40025 COSPAR designator 2014-033-R

Frequencies:

*Uplink:* 435.035-435.065 MHz LSB

• • 12KhzDownlink:* 145.935-145.965 MHz USB

We kindly request you to share your experiences with the BB so everyone can benefit from operating tips and tricks, as well as being up-to-date on the status. We would also welcome any observation related to the transponder behaviour when the AX.25 beacon comes on.

73 and have FUN

Wouter Weggelaar, PA3WEG AMSAT-NL AMSAT-UK