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PCsat



PCsat users:

We are turning off PCcsat's digi for the next few days. Through the
valiant efforts of our  command stations in the sourthern Hemisphere over
the last 5 days, we are  still unable to get PCsat on a positive power
budget.  So as a last effort, we are turning the digi off.

Even if it appears to be ON, DONT USE IT.  That simply means it has reset
back to ON and we have not  yet had a chance to command it back off for
this orbit.

Every few months, PCsat gets into this worst case scenario as follows:
1) On RESET, dual redundant receivers come ON for best command potential
2) With the loss of our -Z panel, and 35% eclipse season, the result is
   a negative power budget that runs the batteries down in eclipse.
3) No problem as long as we keep the receivers off...(after each reset)

BUT during this season which occurs every few months, two things work
against us:

1)  PCsat is only over  the primary command stations in the dark hours
(eclipse) where it is too  late to do anything because the batteries are
already dead or dying.

2)  PCsat is over the USA and Europe during the evening PRIME-TIME hours
and the user load is the worst while PCsat is running on batteries only.

The solution to #1 has been to enlist the aid of our Southern Hemisphere
command stations LU7ABF, LW2DTZ, ZL1AOX, ZR1CBC, and ZR1FN to command
PCsat into low power mode as soon as it emerges from eclipse (morning
their time) so tht PCsat has the best chance to get a full charge in the
65 minutes before the next eclipse.

This has not worked in 5 days so now we are turning off the digipeater as
well to solve #2.  This happened last in December, and we thought that
improving norethern hemisphere sun would improve the situation this phase,
but appraently not enough...

de WB4APR@amsat.org, Bob

PCsat WEB  page     http://www.ew.usna.edu/~bruninga/pcsat.html
ISS-APRS FAQ:       http://www.ew.usna.edu/~bruninga/iss-faq.html
CUBESAT Designs     http://www.ew.usna.edu/~bruninga/cubesat.html
APRS SATELLITES     http://www.ew.usna.edu/~bruninga/astars.html

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