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[aprssig] PCsat recovered!

Robert Bruninga bruninga at usna.edu
Sat Oct 16 15:10:17 UTC 2004


At 1450z I noticed that PCsat's telemetry packets were
at serial number #452 meaning she had not reset for
452 minutes or about 7 hours.  Thus, she lives!

I just commanded her to low power mode to make sure
she stays that way.  Also I did notice that I got one
telemetry value of +150 mA from the NON-WORKING -Z 
panel that is what caused her to fail in the first place.

This could have been a fluke telemetry (I had PASSALL ON)
but it if is real, then this could mean that thermal cycling
of the -Z panel has caused the "open" circuit to close...
The -Z telemetry is only available on the "B" side and that
is the side that downlinks on 144.39 so it is rare to get one
between all the normal APRS traffic on that channel.

And to save power, I have turned the B side to 9600 baud
so that the TX packet time is only half what is is for 1200.
But if you live in a quiet area or anywhere else but north
america, it would be nice to get some telemetry on the B
side.  Just listen at 9600 baud for the once a  minute packet.

Look for packets ending in ...,XX00,1.  The 00 packet is 
the one with the -Z telemetry in it.  It is the value second
telemetry value, and any value above about 50 is a PLUS
current on the -Z panel!

Typical packets might look like:

W3ADO-1>BEACON:T#449,031,085,107,022,213,11111111,0000,1

Here the 085 is showing that the -Z panel is working!

Check out the pcsat web page:

http://www.ew.usna.edu/~bruninga/pcsat.html





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