To: persons interestedAn ccw   , -w- II



.From: Chas. Woodsong



. W6NEY



During recent tests between JA1BLV amd@MM. under very poor
band conditions on 20 meterst we-have.-stiveral-tiues observed
what appears to be very long time delaysAn propagation.



JAIBLV was transmitting ccw. The signal-could no-,- be heard
by ordinary qw methods, or could be@,heard very weakly but not
copied. Tuning of the ccw receiver'showed-a defknite peak
of around 15 dB above the noise floor'-centered'on the



-JAIBLV frequent



The bit-framing could not be acquirell'Clearl'y'. Sometimes there
appeard to be no noticable difference cver-several .01 second
framing settings. Sometimes the signal-was- copiable,,in part,
and with great difficulty, on almost any, framing setting.
(Normally, when framing is .05 seconds off@:even t-he best of
signals can not be copied and usually are not - ever noticed.



While we have not fully ruled out equipment failure or operator-.
error, tbis-appears to be a spreading of the sigr.al over time due
to propagation be several paths which take different times.
But the time delays observed appear to be in the order of
.1 second which seem very long.



This suggests that the current ccw filter design .4A:.s not optimally
reached for such signals. Currently we are transmitting for
full .1 second frames and receiving for a full .1 second frame.
Ttis sug-ests that we might be better off under si@ch conditions

          L-1
if we used transmitted wave form which concentrated the power
in a shorter portion of the frame period. The propagation
rounding would tend to spread thd)s out.



The .@ffect should be less noticed at longer frame lengths.
We plan tests at longer franielengths for comparison.



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