The transceiver is held in
the universal mounting bracket
by two thumbscrews which
allow for adjustment at a
convenient angle.
The bracket includes two
self-tapping screws and star
washers.The mounting must be
mechanically strong,
conveniently located.
Location
Plan location of transceiver and microphone
bracket before starting the installation.
Select a location that is convenient for operation,
yet does not interfere with the driver or passenger.
The transceiver is usually mounted to the
underside of the dash with the microphone
bracket beside it.
Mounting and Connection
1
Hold the radio with the mounting bracket in
the exact desired location. If there is no
interference, remove the bracket and use it as
a template to mark the location for the
mounting screws.
Connecting to an accessory fuse
prevents the unit from being left
on accidentally, and also
permits operating the unit
without running the engine.
Note
In positive ground vehicles the
red wire goes to the chassis and
the black wire is connected to
the ignition switch.
Note
Before installing the CB radio,
visually check the vehicle’s
battery connection to
determine which terminal,
positive or negative, is
grounded (positive is the
larger of the two) to the
engine block (or chassis). A
negatively grounded vehicle
has its negative lead
grounded to the chassis.
4
In a negative grounded vehicle, connect the
red lead of the DC power cord to an accessory
12 volt fuse.
5
Connect the black lead to the negative side of
the vehicle. This is usually the chassis. Any
convenient location with a good electrical
contact (remove paint) may be used.
Plug power cable into back of unit marked
“Power”. Be sure to observe polarity markings.
7
Mount the microphone
bracket on either side of
the unit (driver’s left)
using two screws
supplied. Bracket should
be placed under the dash
so microphone is readily
accessible.
8
Attach the 4-pin microphone cable to
receptacle, on the front of unit and install unit
on bracket securely.
For optimum performance in
passenger cars the ideal
antenna location is on the
center of the roof. Second
choice is on the
center of the trunk.
Note
Because many newer trucks
feature fiberglass door skins, the
outside mirror must be
grounded to the chassis via a
ground strap when antenna is
mounted on the mirror bracket.
Note
3-way Combination
Antennas are also available
which allow operation of all
three bands (AM-FM & CB),
using a single antenna.
However,this type of antenna
usually results in less than
normal transmit and receive
range when compared to a
standard-type “Single Band” CB
antenna. Call 773-889-3087 for
further information.
CB Antenna
Since the maximum allowable power output of
the transmitter is limited by the FCC, the antenna
is critical in affecting transmission distance. Only
a properly matched antenna system will allow
maximum power output. Cobra loaded type
antenna models are highly recommended for
most installations. Consult your Cobra dealer for
further details, or call 773.889.3087 and speak to
a Cobra representative.
1
A standard antenna connector is provided
on the transceiver for easy connection.
Marine Installation
The transceiver will not operate at maximum
efficiency in a boat without a ground plate,
(unless it has a steel hull). Before attempting
installation , consult your dealer for information
regarding an adequate grounding system and
prevention of electrolysis between fittings in the
hull and water.
Use of a mobile receiver at low signal levels is
normally limited by the presence of electrical
noise.The primary source of noise in automobiles
is from the alternator and ignition system.
Typically, when signal level is adequate, the
background noise does not present a serious
problem. Also, when extremely low level signals
are being received, the transceiver may be
operated with the vehicle’s engine turned off.The
unit requires very little current and therefore will
not significantly discharge the vehicle’s battery.
Even though the Cobra 29 LTD BC has an
automatic noise limiter,in some installations
ignition interference may be high enough to
make good communications impossible. Many
possibilities exist and variations between vehicles
require different solutions. Consult your COBRA
dealer or a 2-way radio technician for help in
locating the source of a severe noise.
Antenna Indicator LED
will illuminate when TX if
SWR is high.
Calibrate for SWR (Standing Wave Ratio)
SWR calibration is done to properly adjust the
length of the antenna and to monitor the quality
of the coaxial cable and all RF connections.
This calibration is critical in order to achieve
optimum performance.
Calibration must be made in an
open area (never in a garage).
Vehicle doors must be closed.
No one should be standing near
the antenna. (See your antenna
directions for more complete
3
Push and hold mic button.
information).
4
While holding mic
button adjust the
SWR CAL knob so the
meter needle swings
to the CAL ▼ mark on
the meter (located on the right).
The reading will be slightly
higher on Channels 1 and 40
compared to Channel 20.
5
Note
When switched to SWR position
the meter needle should ideally
be as far to the left as possible.
Anything over 3 is not
acceptable.The antenna
indicator will light. A slight
antenna height adjustment
(higher or lower) may be
required.Repeat relcalibration
steps.
While still holding down the mic button, set
the S/RF SWR CAL switch to the SWR position,
to read the SWR reading.
6
Repeat the same steps two through five
on Channel 1 and 40. This will check SWR for
all channels.