Specifications

40
and should be installed as close as possible to the tuner. It may be necessary to
use several ground rods bonded together to improve the ground contact.
Water pipes are sometimes recommended as grounds and may be used provided
plastic pipe is not buried as part of the system and the following conditions
are met:
a) The water pipe is close to the tuner.
b) The water pipe enters the ground very close to the tuner bonding point.
c) There are no joints or couplings in the pipe that will increase the
resistance path to ground.
d) The water pipe enters soil with good conductivity.
e) A low resistance contact is made to the water pipe.
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Frequently the ground conductivity
will not suffice to provide satisfactory operation of the coupler - almost cer-
tainly the case with well drained sandy, rocky or loamy soils. Therefore, a
counterpoise (artificial ground) must be used as the ground system.
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In a rooftop installa-
tion where there is no existing ground plane, the ideal ground would be con-
ducting surface extending several wavelengths in all directions around the
antenna. On a rooftop, this situation may be approximated by placing a screen
of chicken mesh, copper hardware cloth or similar material over the roof of
the building. More frequently, a counterpoise system of radial wires must be
used. SGC recommends the use of at least 8-12 radials bonded together in the
center. If the antenna is at ground level, the radials should be buried a few
inches below the surface.
66..44 CCoorrrroossiioonn
The ground connections are subject to corrosion and oxidation. All joints must
be clean and the hardware adequately tightened. Joints should be well sol-
dered wherever possible. The joints may be protected by an application of sili-
con grease, and under severe conditions, covered with electrical tape and
waterproof varnish or a durable brand of silicon caulking.
If you are mounting your Smartuner on a vessel where a lot of salt spray is
encountered, it is a good idea to put the wire connections which are exposed to
weather on your 6-month periodic maintenance plan. Then, every six
months, you will be reminded to undo each of the connections, clean, retight-
en and reseal.
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA 98005 USA
P.O. Box 3526, 98009 Fax: [phone] Tel: [phone] or 1-800-259 7331
E-mail: [e-mail] Web site: http://www.sgcworld.com
© 1998 SGC Inc
SG-235 Manual