Ignition Noise InterferenceAntennasUseof a mobile receiver at low signal levels is
normallylimited by the presence of electrical
noise.The primary source of noise in automobiles
isfrom the alternator and ignition system.
Typically,when signal level isadequate, the
backgroundnoise does not present a serious
problem.Also, when extremely lowlevel signals
arebeing received,the transceiver maybe
operatedwith the vehicle’s engine turnedoff. The
unitrequires very little current and therefore will
notsignificantly discharge the vehicle’s battery.
Eventhough the Cobra 29 LTD CHR has an
automaticnoise limiter,in some installations
ignitioninter ferencemay be high enough to
makegood communications impossible. Many
possibilitiesexist and variations between vehicles
requiredifferent solutions.Consult your COBRA
dealeror a 2-way radio technician for help in
locatingthe source of a severe noise.
CBAntenna
Sincethe maximum allowable power output of
thetransmitter is limited by the FCC, the antenna
iscritical in affecting transmission distance.Only
aproperly matched antenna system will allow
maximumpower output.Cobra loaded type
antennamodels are highly recommended for
mostinstallations. Consult yourCobra dealer for
further details,or call 773.889.3087 and speakto
aCobra representative.
MarineInstallation
Thetransceiver will not operate at maximum
efficiency in a boatwithout a ground plate,
(unlessit has a steel hull). Before attempting
installation, consult your dealer for information
regardingan adequate grounding system and
preventionof electrolysis between fittings in the
hulland water.
CB Antenna
7
Note
Foroptimum performance in
passengercars the ideal
antennalocation is on the
centerof the roof.Second
choiceis on the
centerof the trunk.
Note
Becausemany newer trucks
featurefiberglass door skins, the
outsidemirror must be
groundedto the chassis via a
groundstrap when antenna is
mountedon the mirror bracket.
Note
3-wayCombination
Antennasare also available
whichallow operation of all
threebands (AM-FM & CB),
usinga single antenna.
However,this type of antenna
usuallyresults in less than
normaltransmit and receive
rangewhen compared to a
standard-type“Single Band” CB
antenna.Call 773-889-3087 for
furtherinformation.
6
1Astandard antenna connector is provided
onthe transceiver for easy connection.