16
MAXIMUM RANGE
The maximum range and quality of CB
transmissions vary depending on:
• The type and quality of antenna
used.
• The height of the antenna’s
mounting location (the higher the
antenna, the better the reception).
• The surrounding terrain (moun-
tains and tall buildings limit the
range).
• The weather conditions.
• The number of nearby CBs oper-
ating on the same channel.
• The standing wave ratio (SWR)
between the antenna and the CB.
You can set the SWR by using an
SWR tester (such as Radio Shack
Cat. No. 21-523). Follow the
instructions that come with the
SWR tester.
REDUCING NOISE
The Automatic Noise Limiting (ANL)
circuit helps keep background noise to
a minimum. However, strong sources
of noise, such as your vehicle’s igni-
tion, another radio, or spark plugs may
be more than the circuit can compen-
sate for.
If you operate the TRC-488 with the
vehicle’s engine off, you should not
have any problems with noise. If you
use the CB with the engine on, you can
determine the source of the noise by
turning off the engine and operating
the CB with the ignition set to ACC. If
most or all of the noise goes away, the
problem is in your vehicle’s ignition or
electrical system.
Here are a few hints to help you reduce
or eliminate such noise:
• Replace old ignition wires with
new, high-voltage, noise-suppres-
sion wires.
• Install noise suppressors on your
spark plugs, or install new spark
plugs that have built-in suppres-
sors.
• Be sure that the ground connec-
tion (black wire) is secure.
If problems persist, check your alterna-
tor/generator, regulator, and gauges.
Noise from these sources can be re-
duced or eliminated using bypass ca-
pacitors at the various output voltage
points.
Your local Radio Shack store has a
wide selection of noise-suppression
accessories.
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