My situation is that we have a good surface topsoil; of about two feet
thick and then a few hundred feet of chaulk to the summer water table.....
in winter that rised of course.
I run a dipole at 70ft between two towers and I can switch and remotely
match it as a Marconi T against ground. All the local fences are earthed
to the chalk level with copper rods every 30 ft or so. Also, directly
below the aerial system is my workshop with a metal roof of about 45ft by
30ft.... the sheets are bonded and earthed in five places.
I have also one fence line about 1.5 miles long to the south, another 600
yards to the west, the third is about 25 yards to the north. These are
also earthed about every 30 ft.
The dipole gives reasonable results all the time, but the Marconi T is super
after a long period of rain..... in dry weather just forget it!!
My best Dx on the Marconi is Mike VK6HD with 3 W in pile-ups and I've done
that twice now. The second time I completed the QSO with 1w, but as the
call was made with 3W I still call it a 3W QSO. I should add at this point
that conditions on both occasions were superb with Mike S8 on the S meter!
My Idea is that the local earthing and workshop roof make the Marconi look
good RF wise, but the Dx capabilities in dry weather seem to prove to me
that it's the long earthing system that makes it a Dx aerial...
Sorry so long winded but ideas please!
73
Ian, G3ROO
_______________________________________________
Topband mailing list
Topband@contesting.com
http://lists.contesting.com/mailman/listinfo/topband
|