Re: LF: Fldig Flarq mfsk16

["James Moritz" <james.moritz@btopenworld.com>]

Dear Graham, Gary, LF Group,

Thanks for the QSOs this evening...

It seems MFSK16 works quite well in the presence of QRN, which is quite 
strong here tonight. There is always MFSK8 and MFSK4 to try as well.
The Flarq ARQ mode was quite interesting, although probably not what you 
want for a "traditional" QSO. I imagine it could work quite well when you 
actually want to transmit quite a large amount of text over a period of 
time, rather than "ur 599 wx not vy gud" etc. I set the packet length to 16, 
the smallest possible, with the idea of maximising the chances of receiving 
un-corrupted packets under weak signal conditions, at the expense of 
increased ARQ overheads. Timing out seems to be a problem; there are options 
to configure number of retries and timeout period, which it would probably 
be sensible to set to more than the default 5 retries / 60s timeout due to 
the nature of the QSB on 500kHz. Also, there does not seem to be a way of 
forcing a disconnection if you lose contact with the other station - I think 
this was causing trouble when I  was trying to "connect" G4WGT after G0NBD 
had timed out.
Cheers, Jim Moritz
73 de M0BMU