Regarding grounding and an RF service entrance:
Parallel conductors spaced apart provide low inductance similar to that
provided by flat conductors, as described in Polyphaser's book and other
sources.
That can simplify bringing ground as well as coax into the house.
I used a steel box on the outside of the house. It has a door for access to
the lightning arrestors mounted on an aluminum plate inside it. Five conduits
penetrate the wall into the house, and five holes in its bottom admit coax and
ground lines. Five #6 ground lines enter, one in each bottom hole, and bolt
through appropriate hardware to the aluminum plate (copper must not contact
aluminum). The distance across is 10". Five ground lines also enter the
house, spaced across 10". Lightning arrestors for each coax and antenna
rotator are mounted on the aluminum plate. Anti-corrosion paste is used
liberally.
The distributed ground wires are equivalent to a 10" wide conductor entering
the house and introduce no need to cut a wide hole. Inside the house, I
connect them to conventional copper strap leading to a grounding system for the
radio and interfacing computer equipment.
Below this service entrance is the perimeter ground wire, which connects to
other utility ground rods as well as additional ground rods, ideally every
16'. Radial ground wires originate from the rod under the service entrance and
are grounded every 16' for 32 or 48 feet from the perimeter ground, thus
achieving the distributed ground desired. The five ground wires from the
service entrance are connected over about 10", one to the ground rod under the
service entrance, one each to the perimeter ground either side of that rod, and
the other two to radials from that ground rod.
I've used conventional clamps for connections in the ground system, but welded
connections would be better. Clamped connections should be serviced at least
annually and protected with anti-corrosion compound.
I also installed suppressors at the power and phone line entrances and at the
power outlets supplying the radio and computer equipment.
I assembled this after studying Polyphaser and other publications.
I had lost a modem about every year prior to installing this suppression and
ground system and have lost none in the two years since installing it.
73 de WOØW
________________________________________________________________________
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same place that pays for the hosting of this list: The eHam Store.
Order online at http://store.eham.net.
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