Noise suppression.
A very common source of
excessive noise is the ignition system
of a CB owner's vehicle. If you suspect
this is true, simply turn off the ignition
and set the key in the accessories
(ACC) position.
This way you’ll provide power to
the transceiver, minus any ignition
interférence that might exist. If the
noise goes away, you know instantly
that the ignition system is the culprit.
Still, there are a number of places
in the ignition system where noise can
originate.
Sparkplugs and sparkplug wires
are probably the worst noise
producers. To eliminate this kind of
noise, you can fake any of four simple
measures: (1) Install résistive
sparkplug suppressors, (2) resistor
sparkplugs or (3) resistance-wire
cabling, between plugs and the
distributor and also between the
distributor and ignition coil. (4)
Replace old plugs and sparkplug
wiring and properly tune the engine.
This generally cures most noise.
Many cars corne suppressor-cable
equipped. If yours didn’t (consult your
vehicle owners manuał or dealer
service department to be sure), you
can get it at any auto supply store
and, given a moderate amount of
mechanical ski11, install it yourself.
Caution: Do not undertake any
ignition-system repairs or
modifications without either
Professional help or some automotive
service expérience.
Generator-brush sparking can
create an annoying “whine.” It’s
caused by a dirty commutator, and is
eliminated by polishing its surface with
fine-grade emery cloth, and cleaning
grooves with a small, sharp tool.
Voltage regulators can cause a
“hashy” sound in your CB when relay
contacts jitter open and closed when
the battery is fully charged. To
eliminate this noise, mount coaxial
feedthrough capacitors at the battery
and armature terminais on the
regulator box.
Alternator slip rings should also
be kept clean and good brush contact
maintained to minimize CB noise.
In addition, single-contact
alternator regulator boxes need a
coaxial capacitor at the ignition
terminal. Double-contact units should
hâve a second capacitor at the battery
terminal. Shielding between the
regulator and alternator may be
needed as well. Be sure to ground the
shield at both ends.
Infrequent, though real, noise
generators like your car’s heater fan,
turn signais, electric Windows and
w indshield-w iper m otors can also be
silenced with a coaxial capacitor
(consult your serviceman).
Wheels and tires can also cause
CB noise. Wheel noise is eliminated by
putting static-collector springs
between the wheel spindle boit and
grease retainer cup. Tire static can be
quieted with antistatic powder applied
inside each wheel.
Antenna corona-discharge noise
— most frequently occurring with
sharp-pointed “whip” models — can
happen just before or during electrical
storms.»The only cure is for the storm
to blow over or pass
To Next Page
Loading...
