From HB9ASB, JN36pt
Somehow my last e-mail to this reflector got lost, so here again some
explanations:
In the meantime I've repeated the tests with two other receivers
(Watkins-Johnson WJ8888 and Icom IC765): the results are the same.
I've used the term "blind test" because of an automatically keyed TX
with a random text. This helped my to find the point where the signal
was just strong enough to copy. Unfortunately I could not also switch
the power level automatically. Anyway, I think I came quite close to the
"threshold point": In all cases the signal was no longer to copy when I
lowered the TX output by another 3dB.
Of course I've changed the dwell time and the averaging control to
higher levels for the tests with longer dot periods. But as Andy said,
longer dwell time is probably just a waste of time (the computer is
waiting!) and this may be the reason why longer dots give no advantage
under normal condx. However, in situations when longer periods of
reception are wiped out by heavy QRN or QRM (Luxembourg-effect), a
longer dot-time may help.
73 de Toni
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