Tidying up at the beach

During the past 24 hours, I decided to gather more WSPR data by comparing identical (elevated, 1/4 wave vertical, 2 radials) antennas, one located at the seaside, the other at home.  Previous work had tended to compare a mobile whip with a delta loop at home, or used more distant stations for comparison, both approaches having advantages and disadvantages.

'Home' means 100 metres up on a ridge overlooking the sea.  In the direction of the eastern seaboard US, the sea is about 12km distant, and visible.  In the direction of the west coast US, the sea is 7km distant, and visible.

West coast Wales, listening to the US.  My old runaround car has hit a fair few boulders in its travels!

Whilst I had been back-calculating to compensate for power output differences between my own station on the beach and my reference inland station, G0CCL, I had to abandon this method.  That was because there is a very clear and consistent disparity between reception reports at 5W, and those at 1W.  That is probably an effect of the ionosphere and/or noise local to the receivers, and not anything to do with G0CCL.

So, the simplest option was to resort to listening instead.  This also removed the 20 minute delay in propagation changes that occur as a result of the longitude difference between me and G0CCL.

The outcome of the evening listening to the US was a +10dB advantage to the sea side.  The range was +14dB to +4.5dB.

To the east, in the morning, there was a +12.5dB advantage to the sea side antenna.  The range here was +19dB to +10dB.

East coast listening in the morning.

In both cases, there were several stations that were not heard at all by the vertical at home.  In the case of JA9TTT, which was heard at -14dB at the seaside, and not at all back home, the inferred signal enhancement there, based on WSJT-X's detection limit being -34dB, might be as high as 20dB.  I've seen up to 29dB enhancements with other stations in earlier work.

So, I've now run out of time and energy for this work, and will soon ruck out of luck with the very fine weather we have had for most of September.

The basic story is that being at the coast, without actually having to be in the water, typically boosts your performance by roughly 10dB, or a ten-fold increase in signal, with a good number of paths showing enhancement of about 14dB (25 times), and occasional ones nearly 30dB (1000 times).