If the frequency in question is only 1.8 mHz, then I vote for ocean. Here's
one example: When I worked at Endicott Island in the Arctic Ocean it was
common to listen to the AM broadcast band on the car (or truck) radio.
Through a series of causeways and bridges, one could leave Endicott and
drive to the mainland. Invariably the broadcast stations would start fading
as soon as one crossed the beach. Even in the winter when there was a solid
icepack. Intrigued, I tried tuning up at the high end of the broadcast band
around 1600kHz. I was able to receive many European stations on my car
radio up there while at Endicott, but they all faded when I hit the
mainland. The difference was huge - solid copy as I crossed the beach,
inaudible within a mile or two inland. Now hundreds of feet of Permafrost
is a pretty poor ground, so the results might differ elsewhere where the
change in grounds is not so radical between ocean and shore. Another
thought is that trans-polar signals at MF prefer vertical polarization,
paths through lower latitudes might show more horizontal polarization and be
less affected by the earth underneath. On 160, I did compare the Endicott
site twice with the guys at the Prudhoe Bay camp. Their camp was about 10
or 12 miles inland as I remember, and we were both using similar antennas.
The island site of Endicott was much louder and heard much better over the
pole on top band. While I believe solitary hills may be better on the
higher HF bands, salt water makes that old top band sound like 20.
Dan KL7Y
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