Alex K2BB wrote:
>I cannot add more wire radials - there are 3 radials already each way
>from the tower, 3 feet apart.
With so little ground area, you'll need to try much harder than that -
but believe me, it WILL be worth it.
>I remember reading about some aluminum "chicken mesh" used as radials.
>I think it might help. Where do I get it?
>
Broad strips of radial material will definitely be better. Probably the
key reference is still the article by Robert Sherwood (yes, *that* Rob
Sherwood) in Ham Radio, May 1977.
But don't use chicken mesh of any kind! It's great for expeditions and
Field Days but in a permanent installation it will break up in the
ground (a former owner of this house had kindly left some test samples)
and will be a nightmare to remove.
I'm having much better experience with heavyweight galvanized "stock
fencing", about 3ft wide and divided into 6in squares which are plenty
dense enough for HF. This is much stronger and more heavily plated than
chicken mesh, and surprisingly it was also cheaper.
Although galvanized steel cannot equal traditional copper wire for
conductivity, the losses are more than offset by the greater ground
coverage. (Remember also that the skin effect concentrates the RF
currents into the more conductive zinc plating; and because it's a mesh,
the current density in the individual wires is quite low.)
For connecting the strips of fencing together at the base of the
antenna, these 4-way clamps proved to be ideal (sorry, there seems to be
either no image or the wrong image for this product):
<http://www.rappa.co.uk/products/151-four-way-line-clamp-25-pack>
There's sure to be something similar at your neighborhood NYC farmer's
store.
--
73 from Ian GM3SEK
http://www.ifwtech.co.uk/g3sek
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