Listening to FreeDV Digital Speech with an RTL-SDR
Over on YouTube user BSoD Badgers has uploaded a video showing his reception of FreeDV digital speech at 14 MHz. He uses SDR# combined with the FreeDV software to decode the signal.
FreeDV is a open source software application that allows digital speech to be sent at HF frequencies in a 1.25 kHz wide signal. The same software can be used on the receiving end to decode the signal into speech.
http://www.youtube.com/watch?v=TSUQLb4mFKo
This the mode is better for the voice cw, same like the old Coherent CW.
The compression makes him sound an awful lot like a speak and spell 🙂
Its a fun little mode, but catching it in the wild is uncommon as its not widely used. and the fact that we can do it with a cheap stick from china and an upconvertor makes it just that more fun! 😀
Impressive stuff at such a low bitrate!