BATC Forum

Had a play late last week with gnuradio and the DATV-Express.

I made a 'bodge' of an SSB transmitter, gnuradio flow path screenshot is attached.
You could use an RTL-SDR dongle as the rx and a changeover relay to make a full ssb transceiver.

Audio is taken in from the soundcard and converted to complex IQ signal, the upper sideband of this complex signal is filtered.
This is then goes into a very crude AGC circuit and then into a resampler to take it upto 2048ks/s complex signal for the DATV Express output.

I will put some more info on my website when i get time, i used the newer version of gnuradio so making the gnuradio file available will be tricky as most are still uing the older version so it would not work.
The gnuradio DATV Express sink module is here: https://github.com/csete/gr-datvexpress

73

Rob

Hi Rob M0DTS,

Thanks for sharing your efforts with GNURadio and DATV-Express to transmit SSB.

You showed a plot of the FFT spectrum for SSB (very clean). Can you post a screen-capture of your SSB signal using a Spectrum Analyzer? I am just curious of any differences between the "math model" and the "real world".

73...de Ken W6HHC