The title was changed to better describe the original question.
This topband newcomer asked what had happened to the topband conditions, given
the rare intercontinental Low Power to Low Power CW QSO’s,
even when riding upon sun propagation enhancements, as noted in this log, during
the last 6 or 7 winter topband contests.
(the last 3 years = topband newcomer)
At such distances, HP to my LP comprise the majority of the QSO’s, the amount of
LP to LP can be counted on one hand.
It is clear that LP to LP QSO’s to be very common, within eg. 3000km range (cfr.
TBDC) but once beyond, LP to LP QSO’s are exceptional
for non-exclusive callsigns.
This is with 100W and (a remotely fed ATU under) a quarterwave inv L (Tx) at
15m, down to 11m, with 50 radials of different lengths.
And with an unterminated Beverage (128m) as Rx-antenna (pointing NW/SE), on
farmers field with plenty of CM choking.
Summarizing your feedback: Two main causes seem to contribute:
1.Noise:
It would be interesting to learn by how much the noise floor has been raised
over more than half a century of topband operation…
How many dB’s were lost over time?
2.Co-channel interference:
I understand a very large concentration of NA-participants in contests to affect
their weak signal Rx-capabilities in a given bandwidth, losing a layer of weak
stations.
But even while Rx-ing (on the mid-size Beverage) during quiet (non-contest)
morning sunrise hours, signal levels (from NA) are so low and provide nowhere
the feeling,
a QSO with another similarly equipped DX-station to be possible…
As expected the log indicates, these handful LP to LP- QSO’s to have all
occurred during these timed & QTH-selective propagation enhancements.
73,
Michel, ON7EH
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