[amsat-bb] EO-79 transponder activation

Wouter Weggelaar wouterweg at gmail.com
Mon Dec 28 09:09:10 UTC 2015

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.

> 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

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