[amsat-bb] RAFT Satellite PSK-31 mode next week

Robert Bruninga bruninga at usna.edu
Wed Jan 10 14:40:33 PST 2007


Next week, we will enable the PSK-31 transponder on RAFT.

This transponder is 28.120 USB MHz PSK-31 SSB uplink and 2
meters FM down.

Both RAFT and ANDE (and PCSAT-1 this week) are working fine on
orbit for those with a big enough OSCAR satellite array to hear
the weak 2 meter downlink.  PCSAT-1 is much stronger and  has
passes that are almost 15 minutes in length and can be worked
horizon to horizon with a good beam.  ANDE and RAFT are only
usable above about 10 to 15 deg with a good beam for only a
central 3 minutes or less.

RAFT packet-to-voice mode has been enabled for the first 3 weeks
and several stations have made contact...  See web page:
http://www.ew.usna.edu/~bruninga/ande-raft-ops.html

Next week starting Tuesday 16 Jan, we will enable the RAFT
PSK-31 transponder for similar experiments.  Here is what it
takes once the PSK-31 mode has been enabled:
1) Read the user-service-agreement on the above web page
2) Someone in the footprint must do a packet CONNECT RAFT
3) That will bring up the 10m RX and 145.825 TX for 1 minute
4) Anyone sending PSK-31 or CW on 28.120 MHz USB should be heard

The transponder will time out after 1 minute (maybe later we can
extend that time depending on usage).

Remember that the footprint of RAFT is an order of magnitude
smaller than PCSAT-1 and so it is hard to hear except when a
high pass and the duration is only a few minutes.  With PCSAT-1
fully alive this week and next, we are seeing over 80 different
stations (the maximum depth of the live capture page
http://pcsat.aprs.org ) in under 8 hours.

Just today another satellite was launched onto 145.825 so now
there are 5 satellites there!
PCSAT-1, ANDE, RAFT, UO-11 and now Pehunesat.  All but UO-11 use
standard 1200 baud AX.25 packets.

Bob Bruninga
USNA Small Satellite Lab




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