Congratulations Laurie, it has been a long haul but fascinating to see
some progress. Just another few dB would make a big difference and I
think there is still a lot of scope for improvement in Rx antennas.
Mike ZL4OL
Yes, receiving techniques still have a long way to go. In the back of
my mind for development (when paid workloads permit) is a narrow
beamwidth uni-directional antenna for receive. This should
dramatically reduce noise levels over the conventional omni or
broadly bi-directional antenna. There is also some work to be done on
electrically steering the vertical angle of reception, either to
boost low angle DX or to reduce high angle noise. We also need to
understand the nature of the ionospheric noise that accompanies DX
openings (Is it static or man-made? Is it from the ionosphere itself
or just reflected by it? Does it come in at the same angle as the
signals?)
Another technique waiting to be developed is pseudo-synchronous
transmit and receive. By that I mean something between QRSS (which is
unsynchronised) and proper synchronisation using complex techniques
that have so far failed to become popular. The fact that Markus could
gain information from comparing the Tx and Rx timing proves this.
With QRSS60 or 120, the synchronisation error could be of the order
of a few seconds!
There are probably some 6 - 10 decibels out there just waiting to be
picked up!
Mike, G3XDV
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