[amsat-bb] PSAT - power requirements

[Koos van den Hout]

Quoting Robert Bruninga who wrote on Thu 2015-05-28 at 17:40:

> What we really need (BEFORE this happens) is for everyone to give us
> feedback as to the minimum power they needed to maintain a minimum signal
> in the passband and of course, what kind of antenna they are using under
> those conditions.  And this is best early on when there are only 1 or 2
> usewrs at a time..
> 
> If you don't yet have PSK31, but want to get some data, team up with an HF
> friend in your area and ask him to just transmit for the next 10 minutes
> and you can then receie his downlink while commenting on his signal
> strength throughout the pass.

I decided to play the role of the HF friend and Jan van Gils PE0SAT was
kind enough to record the downlink for me in a pass that started at 09:59
UTC this morning for me in JO22NC.

The short conclusions:

- I needed 20 watts on HF to get through the satellite (when the telemetry
  signal was active) and produce a readable signal.

- The automatic switch in the transponder does not recognize PSK31 from
  earth very well. Every time it switched off when the beacon packets
stopped, even with reasonable strong PSK31 from earth.

The complete story of how this was done and the telemetry seen at

http://idefix.net/~koos/newsitem.cgi/1433017519

                                     Koos van den Hout PD4KH

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