[amsat-bb] Re: SSTV Active This Morning
Gordon J. C. Pearce MM3YEQ
gordonjcp at gjcp.net
Wed Oct 22 02:02:23 PDT 2008
Nothing heard on the 0834UTC pass.
Both recordings are available from:
Not that they're terribly interesting. I'll make the whole lot
available once I've had a chance to sort them all out. I'm really
annoyed I missed the "last" pass yesterday - apparently there was some
voice traffic over the UK.
Just as a bit of background to how I'm doing this, I have my Trio TR7730
and homebrew omni at home, with the speaker output hooked up to a laptop
which I can connect to remotely. I can then ssh in and tell the laptop
to wait for a while then start recording, based on the time-to-AOS from
So, for instance, if I look at gpredict I see "ARISS AOS in 1:15:xx". I
connect to the laptop and type in "sleep 75m; arecord -r22050 -f S16_LE
-d 600 pass3.wav" and then leave it. Once the pass is finished, I
encode the .wav file, upload it to my server, and then grab it from work
where I can sit and listen ;-)
Unfortunately I can't tune the transceiver to compensate for Doppler,
and in a couple of the recordings you can hear this. It seems to be
worse as the ISS goes away, I haven't worked out why this would be yet.
My plan is to automate the recording by working out the passes and
having it kick off the recorder. Now since the transceiver has "UP" and
"DOWN" buttons on the microphone, I could probably tell it to tune up
and down 5kHz by toggling pins with the printer port.
Anyway, considering how simple the equipment to receive the SSTV and
voice signals from the ISS can be, I'm quite pleased with my results. I
can't wait until they do some more!
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