Hello,

Over the weekend I have integrated the 700C Codec 2 with the FreeDV API 
and FreeDV GUI programs.  The 700C FreeDV mode uses the 700C codec and 
the 700 bit/s coherent PSK modem developed a few years ago.  It works OK 
for me between radios on the bench.

With Brady's help, the 800XA mode has also been added.  This also uses 
the 700C codec but is teamed with the 4FSK modem we have developed for 
VHF/UHF work.  The extra 100 bit/s is for frame synchronization. This is 
a bit experimental for HF work, but has the advantage of being a 
constant power waveform.  I tested it today and managed to smoke up the 
balun in my end fed antenna (which is rated for SSB I guess not CW)!

On my bench tests 800XA still has issues with losing sync with non-flat 
SSB filters, Brady and I will work on that over the next few weeks.  The 
same modem is working really well with 100 kbit/s UHF SSTV:

   http://www.rowetel.com/?p=5344

The FreeDV code is all checked in, so some of you might like to build 
and try it it.  We will look at getting some Windows versions built shortly.

It's early days for 700C and 800XA.  My first goal is to see if FreeDV 
700C works at least as well as FreeDV 1600 in terms of speech quality 
and robustness.

Next steps will include making 700C more robust to HF channel issues, 
and another lap around the codec development to see if we can improve 
speech quality.  Once we are happy that it's an improvement on FreeDV 
1600 we'll see about a SM1000 port.

Thanks,

David


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