From: "Mike Dennison" <mike.dennison@ntlworld.com>
To: rsgb_lf_group@blacksheep.org
Date: Tue, 12 Apr 2005 13:38:06 +0100
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Subject: Re: LF:  G3AQC in ZL
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> 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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