SSTV Robot OZ9STV with USRP and WBX

I was fooling around with the USRP / WBX on the 2 meter band tonight when I suddenly stumbled upon some very strong SSTV transmission. It turned out to be the OZ9STV robot located only a few kilometers from me. That explained why I had more than 40 dB SNR even though I was only using a bad whip antenna indoors.

Neither my Linux computer nor my iMac had any SSTV decoder software installed but a quick search lead me to MultiScan, which is a free and very well functioning SSTV app for the Mac. The receiver I used was the Simple GNU Radio FM Receiver posted few weeks ago.

I have recorded a few transmissions from the robot. This beacon image is transmitted twice every hour if there has been no activity for at least 3 minutes:

Otherwise, the robot transmits the last four images received every 10 minutes:

There are more recordings of the beacon on my live GNU Radio channel on Ustream. Thanks to @jetforme @jdpsyntelos and @loredanap for stopping by!

Next time I will also include the USRP spectrum in the broadcast.

Author: Alexandru Csete

Embedded software engineer in the satcom industry during the day. Radio amateur and SDR hacker during the night.