I’m trying to get a simple PSK loopback working in GRC, File Source ->
Mod -> DPSK Demod -> Unpacked to Packed -> File Sink.
On Ubuntu 12.10 x64 (build-gnuradio a few days ago), the sink file winds
with leading 7 bytes x00, 3 bytes plus one bit noise, four mangled bits,
then my correct bitstream. But the odd bit causes the entire remainder
the bitstream to be right-shifted by one. Throttling doesn’t seem to
Interestingly enough, using MSWin7, I get 6 bytes x00, 2 bytes noise, 26
bytes mangle, and then a correctly aligned stream of bytes (other than a
mangled sequence from about bytes 100-107).
Am I missing something to provide symbol timing recovery?
The GRC file is at