AMSAT-UK

///////////////////////////////////////////
AO-73 in continuous transponder mode

Posted: 21 Dec 2015 06:21 AM PST
http://amsat-uk.org/2015/12/21/ao-73...nsponder-mode/

AO-73 (FUNcube-1) Image credit Wouter Weggelaar PA3WEG

The amateur radio satellite AO-73 will be operating in continuous
transponder mode throughout the festive season until the evening of Sunday,
January 3.

Why not take full advantage of this activation and get your 73 on 73 Award,
details at http://amsat-uk.org/funcube/73-on-73-award/

AO-73 (FUNcube-1) website http://amsat-uk.org/funcube/funcube-website/

FUNcube Yahoo Group http://amsat-uk.org/funcube/yahoo-group/

///////////////////////////////////////////
EO-79 transponder activation

Posted: 21 Dec 2015 03:53 AM PST
http://amsat-uk.org/2015/12/21/eo79-...er-activation/

EO-79 and EO-80 Image Credit ISIS

On December 21, 2015 at 1038 UT, the EO-79 transponder was 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 #Â*Â*Â* 40025

COSPAR designatorÂ*Â*Â* 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 145.815 MHz and consists of
AX.25 frames on BPSK. More details about the downlink can be found on the
ISIS Ham Radio page at http://isispace.nl/HAM/qb50p.html

We kindly request you to share your experiences with the AMSAT Bulletin
Board 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

Mike Seguin N1JEZ notes:Â* I found my downlink after setting my uplink +12
kHz from published spec

Graham Shirville G3VZV says that due to platform sharing considerations the
FUNcube transponder on EO-79 uses 1/4 wave monopole antennas rather than
the full dipoles used on AO-73. The actual effects of this difference in
practice may be interesting to observe.

AMSAT Bulletin Board (AMSAT-BB)
http://www.amsat.org/mailman/listinfo/amsat-bb

Satellite Tracking http://amsat-uk.org/beginners/satellite-tracking/