Q-Mac HF-90 Operations & Installation Manual page 52

Section 8.2
Power source
Grounding
Antenna
Where a bull bar is fitted, a vehicle whip antenna should be
mounted on the front of a vehicle (on a special bracket
welded to the bull bar, on the passenger side of the vehicle).
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The HF-90 must be properly connected to a suitably
charged 12 - 24 Volt battery. If the set does not
receive adequate voltage it will not operate properly -
there may be speech distortion on transmit and the
LED display will begin to dim.
The power cable supplied by Q-MAC is designed to
minimise voltage drop between the vehicle battery
and the HF-90. Installing a light core cable will
result in severe transmitter distortion and could
damage the radio.
In a vehicle installation, Q-MAC recommends that
you fit a cartridge fuse (20 Amp) in the active wire,
close to the battery. This will protect the power cable
from the risk of damage through short circuit.
In a vehicle system adequate grounding is provided
by the metal body of the vehicle. The area of metal
is sufficient to allow good ground coupling.
Ensure that the ground on your antenna system
(tapped whip antenna or automatic tuner) makes a
good connection to the chassis of the vehicle. Failure
to do this may substantially reduce the radiation
efficiency of the antenna.
HF-90 Operation & Installation Guide