Codan Envoy Reference Manual page 435

Earthing the transceiver in a fixed station
A good RF earth is essential for efficient operation of the fixed station. The transceiver
chassis should be connected to earth via the earth screw on the rear panel of the
transceiver. Use a copper braid of at least 12 mm (½ in) width to connect the
transceiver to the earthing point.
NOTE:
All individual units in a fixed station should be earthed to prevent RF interference
corrupting the data and audio circuits. Equipment that requires earthing has an earth
screw fitted. To achieve good earthing, connect separate earth braids to the earth
screws on each piece of equipment and connect them back to the same earthing point.
NOTE:
An adequate earthing system is necessary for:
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Related links:
Electrical safety
You must use correct wiring techniques to provide electrical safety for the fixed
station.
Related links:
Static drain
In some cases, wind-driven particles, such as dry sand, may charge the transceiver and
ancillaries to very high voltages above earth. Usually the low-impedance protective
earth connection prevents high voltages from building up. In the event that the
protective earth is disconnected or does not exist, as for a solar-powered fixed
installation, these high voltages may occur.
If the voltage of the electrostatic charge becomes sufficiently high, a flashover could
occur between the charged parts and earth. The energy released at flashover depends
upon the voltage of the charged parts to earth. This energy generates a steep wave
front, which may cause failure in the front end of the transceiver or result in damage
elsewhere.
WARNING: A flashover may result in the failure of the basic insulation of a
E ™ T R
NVOY RANSCEIVER EFERENCE
Keep the earth braid as short as possible.
Ideally, all earth braids should connect directly back to a single point
to prevent earth loops.
electrical safety
static drain
noise reduction
Electrical safety on page 413
Static drain on page 413
Noise reduction on page 397
Wiring techniques on page 411
mains-energised transceiver supply, causing an extreme safety hazard.
To avoid a flashover, ensure that the transceiver is correctly earthed.
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ANUAL
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NSTALLATION
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IXED STATIONS
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