On Tue, 30 Dec 2008 14:50:00 +0000, doktorij@bellsouth.net wrote:
>Jim,
>Nahhh, NLI is easy ;o)
>
>Try LAX on the top band. Wasn't so bad when Earl K6SE was still
alive
>and active, but not so "easy" any more...
In both cases, a direct result of limited antennas. Here near SF, we
work a bunch of LAX, SB, and SDG, but not many of these guys have the
antennas to make it to the east coast.
>Maybe we could talk some of the "population" into moving to say NNY
or ND? ;o) No worries about city lots there.
A year or so ago some of the MN guys did a DXpedition to ND for a 160
contest. It would also be nice if someone did that for VE4!
>Something else I recall seeing at Dayton, a more expensive option,
but
>maybe worth looking at if one is serious, was pool grounds. This
stuff
>is bonded heavy gauge copper wire in a grid and comes in rolls (five
>foot wide by 50' long I think). It should look like a "solid" copper
>sheet to RF on 160, 80 and 40. You may have seen something similar
in
>your work. This is meant to be buried and last in the ground. I
>believe it is for meant to be for lightning protection.
When I worked in broadcasting MANY years ago, a very heavy duty
version of this kind of thing was installed in a good-sized grid
around the base of AM broadcast antennas, especially directional
arrays. As an intern from EE school, I spent much of a summer helping
the chief engineer silver-solder the ground system for a 4-tower
array on 930 kHz.
The reason this is a VERY good idea is that the current distribution
in a radial system is highest close to the base of the antenna,
falling off as you move away, so having a very low impedance close to
the tower is more important than at a distance.
73,
Jim K9YC
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