Hills, Sloping Ground and Cliffs

This winter's surprise has been the finding, mediated by objective WSPR tests, that my simple equipment wire, 80m inverted L, is putting out the strongest signal of any station from the EU on DX paths.  By this, I mean, typically, the path to the US.

Is this self back-patting?  No.  I have tested many antennas, and many are useless.  Horizontal antennas usually fit into this category for this QTH.

A hill by the sea.  The perfect DX location!

What is going on?  There are people across the EU with very capable antennas - a few full-sized quarter wave GPs, half-Ls like mine, and probably infinitely more experience and care behind them than I will ever have!

The answer is both interesting and useful for others to note.  Firstly, this QTH has reasonably steep sloping ground in all directions bar to the NNE.  The slope is 6 degrees for just about all of that horizon, being a bit steeper to the north.  This is without doubt a very important feature in obtaining the best performance from simple wire antennas.  I have noted the same phenomenon with delta loops for 20 and 17, vertical GPs and end-loaded dipoles for 20m.

Secondly, the surroundings of the antenna are clear of any substantial buildings.  Our home is a small Welsh cottage, nestled into the hillside.  There are some electricity supply lines of domestic ratings nearby, but these seem to have little or no effect, apart from a degree of de-tuning if you place an antenna too close!

Lastly, and perhaps of little comfort to others unless you live in South America or Australia, is the very high degree of mineralisation due to the QTH being on top of an old hydrothermal vent, more latterly a copper mine.  It is almost certainly soluble iron, and not other minerals, that is responsible for the excellent ground conditions.  Digging a deep hole for my tower some years ago revealed a thin layer of soil, a thin layer of red clay - which is known to particularly enhance RF ground conditions - and then very friable ground-weathered shale that has dissolved iron slowly flowing around within it.

So, whilst the latter element is probably very rare in coincidence with a radio station, the message about sloping ground and an environment as clear of obstructions as possible is something anyone willing to pack their kit onto even a modest hill, cliff or mountain should be able to benefit from. 

And of course, don't forget to try sticking a quarter wave GP at the surf line, where you will really see some spectacular benefits!