I want to say thanks very much to all who replied to my earlier post.
Not only did I get answers to my question, but I had a significant
educational experience.
I feel quite humbled by the effort that people put in not only in to
address the issue but bring me up to speed about terrain effects.
In the process I have had to review what I thought was an intuitive
understanding about effects of ground slope on hf antenna propagation.
I have learned that higher is not always better, that steep slopes are not
necessarily better than gentler ones, and that distance away from the
inflection of a slope has massive effects.
Also relates to an earlier discussion about the effect of sea water: Back in
the early 30s there was data that coastal hf stations could be up to 20dB
stronger than similar installations inland.
Most of us thought it was the salt water. I know now that these were almost
certainly terrain effects.
My original post was made because I needed to make a quick decision whether
to build my tower to 50 or 60ft on at a coastal QTH. (can be seen on p2 of
my website, my QTH is the house with the green roof in the extreme lower
right of the picture).
If anyone else is interested in some of the data that were so generously
provided let me know and I will cc it to this net.
73 and thanks again.
Baz ZL1DD
end
Barry Kirkwood PhD ZL1DD
Signal Hill Homestay
66 Cory Road
Palm Beach
Waiheke Island 1240
NEW ZEALAND
www.waiheke.co.nz/signal.htm
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