Having followed the development of codec2 and freedv, I have attempted
to test out the technology, with varying success. I have had a few 
really nice QSOs
with 100% copy both ways, but also numerous failiures. A few notes below:

- What does the "S-meter" actually show? I have had some QSOs that were 
very good
at down to 5 ( dB SNR ? ) and I have also seen some where SNR has been 
10-12 or so
but with marginal voice decode 20-30%. Pilot SNR or average of all 
carriers or what?

- I have had to upgrade my computer when implementing 0.95.4 Beta, the 
previous machine
running an early version of freedv did that quite well, on a 1.6 Ghz 
machine with 128 M ram.

(part of the problem might be upgrading from Ubuntu 12.04 to current )

- Is it not possible to detect rate / # of carriers on receive and 
*automagicaly* switch between
1600 / 1600W / 1400 V.91 mode? It seems doable?

- I assume TX adjustment is the hardest part of setting up a station. 
Frequently I have been heard
but been unable to decode the other party. Some sort of "reverse beacon" 
would no doubt help people
adjust transmit to maximize decoding reliability.

- Some voices and modulation level "fit well" with codec2, some do not. 
My first DV QSO was with
F6EMT on 20 m, and that was with excellent voice, a really enjoyable 
conversation.
We recently had an "aniversary", when I found Marc on same QRG, but with 
upgraded software and mode
on both ends. 100% copy, vy nice.

- I have frequently used a websdr ( links at websdr.org ) to "see" what 
my signals look like, and determine
if I can be heard. A freedv mode in the websdr software would be fantastic.

- Would it be possible to add "tougher" FEC / Parity check on the TEXT 
info, it would be nice to get
rid of "random" characters interspersed in a message, and possibly alos 
some way to LOG the info.

Ramblings,

SM6FBD / Gullik


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