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FT-410 O
peraTiOn
M
anual
G
rouNdiNG
The
FT-410
transceiver, like any other HF communications apparatus, requires an effective ground system
for maximum electrical safety and best communications effectiveness. A good ground system can contribute
to station efficiency in a number of ways:
It can minimize the possibility of electrical shock to the operator.
It can minimize RF currents flowing on the shield of the coaxial cable and the chassis of the transceiv
-
er. Such currents may lead to radiation, which can cause interference to home entertainment devices
or laboratory test equipment.
It can minimize the possibility of erratic transceiver/accessory operation caused by RF feedback and/or
improper current flow through logic devices.
An effective earth ground system may take several forms. For a more complete discussion, see an
appropriate RF engineering text. The information below is intended only as a guideline.
Typically, the ground connection consists of one or more copper-clad steel rods, driven into the ground. If
multiple ground rods are used, they should be positioned in a “V” configuration, and bonded together at the
apex of the “V” which is nearest the station location. Use a heavy, braided cable (such as the discarded
shield from type RG-213 coaxial cable) and strong cable clamps to secure the braided cable(s) to the ground
rods. Be sure to weatherproof the connections to ensure many years of reliable service. Use the same type
of heavy, braided cable for the connections to the station ground bus (described below).
Inside of the station, a common ground bus consisting of a copper pipe of at least 25 mm (1”) diameter
should be used. An alternative station ground bus may consist of a wide copper plate (single-sided circuit
board material is ideal) secured to the bottom of the operating desk. Grounding connections from individual
devices such as transceivers, power supplies, and data communications devices (TNCs, etc.) should be
made directly to the ground bus using a heavy, braided cable.
Do not make ground connections from one electrical device to
another, and thence to the ground bus. This so-called “Daisy-
Chain” grounding technique may nullify any attempt at effective
radio frequency grounding. See the drawing at the right for
examples of proper grounding techniques.
Inspect the ground system - inside the station as well as outside
- on a regular basis so as to ensure maximum performance and
safety.
Besides following the above guidelines carefully, note that
household or industrial gas lines must never be used in an
attempt to establish an electrical ground. Cold water pipes may,
in some instances, help in the grounding effort, but gas lines
represent a significant explosion hazard, and must never be used.
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