Jim,
Yes , copy was good even during deep fades, I did expect the olivia system
to provide the better link, but as reported last night, the older mfsk
system appeared to give a quite reliable link, Gary and I did try out the
250psk mode , which did work but after loosing the connection, we found it
was not possible to re link whilst using it ... however it appears you can
change modes whilst linked ... I'm not sure the effect the pc speed has on
the system, I was using a p3 1.1 ghz pc and the repeat response did seem to
be a little slow from my station compared with your qso with Gary .. that
should be sorted soon ...
rgds
Graham ..
NB
This is a reply over the use of fldigi with the olivia mode, via the yahoo
digital group may be of interest ,
Olivia cannot be used as the transport mode for flarq unless the
timeout values in flarq are set to their maximums. Even then it is
highly likely that the digital effect of doubling will occur. Please
try to limit your use of flarq to those modes that appear on the
"Mode/NBEMS" menu item. These have been tested and are known to work
very well with the flarg implementation of ARQ.
73, Dave, W1HKJ
--------------------------------------------------
From: "James Moritz" <[email protected]>
Sent: Thursday, February 05, 2009 10:57 PM
To: <[email protected]>
Subject: Re: LF: Fldig Flarq mfsk16
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
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