Today Mark VK5QI took the Balloon ATV transmitter out for a terrestrial test. He carried out line-of-sight testing of the DVB-S payload from BlackTop Hill to the AREG remote site near Tarlee – a distance of 54km!
First test – could he see the signal on the SDR up at the site (RTLSDR, Diamond X-50, no preamp)… yes!
Next, Mark dumped some samples with rtl_sdr, then transferred them back to his laptop. He processed them through leandvb – and got video!!! A bit of fading, but for an omni receiver with no preamp, this is a pretty damn good result!
… and here’s some of the raw video
The MER as reported by leandvb was around 8-11 dB, right on the edge of what is decodable. Still, with such a basic system, a good result!
Based on the path, it is estimated to give us a working range of about 150km from the balloon given a receiving station with 15dBi gain and a good low noise preamplifier.
Stay tuned for more information on how to receive and decode the Digital ATV signal and save the date – we hope to launch the transmitter into the stratosphere on Sunday March 7th. (We also plan on streaming the event on Youtube).
For those who missed it late last year here is a bit more information about the Balloon ATV payload and some minimum signal testing that was carried out.