John,
From the test's ive carried out , the best mode would be a simple 'arq'
system
Non of the send and forget modes are of any use on 500 as you have no idea
if the other end has even seen your signal ,let alone resolved it, that's
unless the station is in ground range and then any mode works , full
break-in cw is about as good as it gets , some of the multi tone systems
give a longer 'clean period' but under qso conditions , require long tx
periods to ensure you have covered at least one 'qsb' cycle
With the noise and deep qsb outage's I would think the best mode would be
'amtor on prozac' with a prf of a few seconds , like a case clock
If only some one could write the source code : just replacing the
conventional 'fsk' keying with 'psk' . the psk giving about 50 % better
accuracy than similar shift 'fsk' and mimic the virtually bullet proof ,
protocol of sitor/amto but simply calm it down a bit , so it doesn't need
a 'tnc' to control the tx/rx windows (bit of a oxymoron that as its
windows that causes the timing problems) ... thanks bill ..
This simple narrow mode would simply work at 30 bauds or so and basically
sit pinging the other end during the outages till it responded , 'link up' =
game on . In a response to a post on the 'multipsk' user site, some one
did repy that they where working on a 'psk-arq' system, but I never managed
to follow it up ..
Rgds
Graham
G0NBD
----- Original Message -----
From: "John Andrews" <[email protected]>
To: "600 meter group" <[email protected]>; "Discussion of the
Lowfer (US, European, & UK) and MedFer bands" <[email protected]>;
<[email protected]>
Sent: Tuesday, January 01, 2008 8:20 PM
Subject: LF: Keyboard modes for 600 meters
As many of you know, Jay Rusgrove and I have been running tests on a
variety of keyboard modes for use in the 500 kHz area. Our focus has been
on modes that work well for casual QSO's and possibly emergency
communication. Resistance to noise and fading has been a prime
consideration.
While this is a work in progress, I have posted an article at:
http://www.w1tag.com/600M_Modes.htm
Comments and suggestions are welcome. Thanks very much to all who have
participated in the tests!
John Andrews, W1TAG / WE2XGR/3
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