Christopher Bartram <cbartram@...>
It depends on the evidence you need ... Certainly, surface ducts occur in the Irish Sea - don't forget the 500km WB QSO between GM and Cornwall back in the '70s. Also, much of the original (WW2) European work on microwave propagation over the sea took place in the Irish Sea basin, and that certainly showed the presence of both surface and elevated ducts.
Whether the path to EA8 would be via a surface (maritime evaporation) duct is a moot point. I suspect that an elevated duct would be more likely, and I'd be interested to hear from someone with professional knowledge of the subject. Certainly, EA8 - GM tropo QSOs have been made at VHF.
My experience with the EA8/CT3/CU paths from my old IO71 QTH was that there were quite regular openings covering up to at least 432 (at that time, AFAIK, there was no legal 1.3GHz activity from EA) and that at times signals were very strong indeed - at times probably well below free-space values. I was a few 10s of km inland, and I strongly suspect that on these occasions propagation would have been via an elevated duct. Stations in more coastal locations experienced propagation to the Atlantic Islands more regularly.
Christopher Bartram MIET
Christopher Bartram RF Design
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