[amsat-bb] PSAT2 Future Operations

Robert Bruninga bruninga at usna.edu
Tue Jun 25 22:53:57 UTC 2019

PSAT Voltages look good.

The PSK31/SSTV downlink appear to be working well on 435.350+/- Doppler,
But you will only see SSTV during daylight passes (Now occuring in the
Southern Hemisphere) where the Solar charge voltage is above threshold (6.8
volts.  THen you should see SSTV images once every 4 minutes automatically
while in the sun.

Northern Hemisphere passes are presently occurring overnight and PSAT2 is
in a 28 degree orbit and not seen at all by high northern latitudes and
most of Europe :-(

PSAT2 APRS digipeating will remain off indefinately while all these other
NEW modes are working.  Do not TX any APRS packets on the uplink.

DTMF Grid Uplinks-to-APRS/Voice will be enabled LATER.

While waiting, spend the next day familiarizing yourself with the PSAT2
APRStt touchtone mode. This mode will let you send DTMF Grid square reports
which are translated to VOICE and to an APRS packet on the 145.825
downlink. Be sure to prepare your radio with your pre-programmed DTMF grid
report IN ADVANCE.  And learn how to send Touchtone from  your radio's DTMF
memory. quickly!  It should take under 4 seconds.  Do not even think of
sending it manually.

Here is WA7MXZ's translator to calculate your onetime DTMF grid report:

See how it works in about the middle of the PSAT2 page:

A successful DTMF uplink will result in a Voice response and an APRS packet
on the downlink for display on APRS radios.  Again, no APRS Uplink in this

This will be painful because of the 4 second uplink transmissions all
colliding on the half-duplex uplink, so PLEASE only attempt your DTMF
uplink once every 30 seconds or longer to give others a chance.  And of
course NOT while PSAT2 is downlinking.

We will advise when this mode is enabled.



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