[amsat-bb] FUNcube-1 transponder now continuously active

[Paul Stoetzer]

John,

These are two separate satellites. FUNcube-1, known on orbit as AO-73,
carries a linear transponder and a telemetry beacon for schools.
During the week, AO-73 normally operates in "educational mode" which
is a 300 mW telemetry signal while the satellite is in sunlight and a
30 mW telemetry signal along with a 20 kHz wide linear transponder
when the satellite is in eclipse. On weekends, the command stations
put it into transponder mode full time since schools are generally not
open, so a strong telemetry beacon for educational purposes is not
necessary.

EO-79, the on-orbit designation of QB50p1, is a satellite that is
designed to test payloads for the QB50 project, which involves a fleet
of 50 cubesats being sent to a very low orbit in order to study the
upper atmosphere. It carries the same style transponder as AO-73. The
transponder is known as FUNcube-3. That transponder has now been
activated for amateur use following the conclusion of the scientific
mission. Unfortunately, the satellite's power system is not sufficient
to power the transponder for a long period (it has a negative power
budget), so the transponder shuts off and the satellite switches to
safe mode when the battery voltage falls beyond a set voltage.

And yes, there is also a FUNcube-2. It's on board UKube-1, an
experimental satellite built by the UK Space Agency. The telemetry
beacon (similar to AO-73's) has been active since the end of the
satellite's primary mission, but there has been no further word of
transponder activation.

73,

Paul, N8HM

On Fri, Mar 25, 2016 at 5:35 PM, John Brier <johnbrier at gmail.com> wrote:
> What is the difference between FC1 transponder mode and the transponder
> payload on EO-79 being on?
>
> 73, John KG4AKV
> On Mar 25, 2016 3:18 PM, "Graham Shirville" <g.shirville at btinternet.com>
> wrote:
>
>> Hi All,
>>
>> FC1 is now in continuous transponder mode for the holiday period. Normal
>> autonomous operation will recommence from late MONDAY evening.
>>
>> As reported earlier today, the transponder payload on EO-79 has also been
>> switched on and, so long as the on board bus voltage stays up above its
>> safe mode setting, then this should also be active.
>>
>> Have a great FUN weekend and enjoy the birds.
>>
>> 73
>>
>> Graham
>> G3VZV
>> _______________________________________________
>> Sent via AMSAT-BB at 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
>>
> _______________________________________________
> Sent via AMSAT-BB at 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