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 [email protected] 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" [email protected] 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 [email protected]. 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

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Sent via [email protected]. 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