Cobra 25 LTD ST User manual

Installation
Installation
Location
Mounting and
Connection
Mounting and Connection
Hold the radio with the mounting bracket in
the exact desired location. f there is no inter-
ference, remove the bracket and use it as a
template to mark the location for the mount-
ing screws.
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 under-
side of the dash with the microphone bracket
beside it.
Not
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 wash-
ers. The mounting must be
mechanically strong, conve-
niently located.
Drill the holes and secure the bracket.
2
1
Connect the antenna cable plug to the recep-
tacle marked “ANT” on the back of the unit.
3
Not
B for installing th CB radio,
visually ch ck th v hicl ’s bat-
t ry conn ction to d t rmin
which t rminal, positiv or
n gativ , is ground d (positiv
is th larg r of th two) to th
ngin block (or chassis). A
n gativ ly ground d v hicl
has its n gativ l ad ground d
to th chassis.
Not
In positive ground vehicles the
red wire goes to the chassis and
the black wire is connected to
the ignition switch.

Installation
Installation
Not
Connecting to an accessory fuse
prevents the unit from being left
on accidentally, and also per-
mits operating the unit without
running the engine.
Not
In positive ground vehicles the
red wire goes to the chassis and
the black wire is connected to
the ignition switch.
n a negative grounded vehicle, connect the
red lead of the DC power cord to an accessory
12 volt fuse.
Connect the black lead to the negative side of
the vehicle. This is usually the chassis. Any con-
venient location with a good electrical contact
(remove paint) may be used.
4
5
Plug power cable into back of unit marked
“Power”. Be sure to observe polarity markings.
Mount the microphone
bracket on the right side
of the unit (driver’s left)
using two screws sup-
plied. Bracket should be
placed under the dash
so microphone is readily
accessible.
6
7
8Attach the 4-pin microphone cable to
receptacle on the front of the unit and
install unit in bracket securely.

The CB/PA button should be in the
CB position.
OperationOperation
Turning On Setting Channel
Selector
Turning On
Make sure the power cord, antenna and micro-
phone are connected to their proper connectors
before starting.
Setting Channel Selector
2
1
Rotate the On/Off Volume knob clockwise to
a normal listening level.
Select one of forty channels and adjust
volume. The selected channel is indicated by
the LED readout directly above the channel
selector knob
1

Rotate the On/Off Volume knob clockwise
the green RT/TX LED and channel display will
be illuminated.
OperationOperation
S-Meter
S-Meter
Swings proportionately to strength of incoming
signal when receiving.
Switch to NORMAL to select desired channel.
1
Selecting A
Channel
Selecting A Channel
Not
Switch to 9 (Emergency) for
instant access to these channel.
To Receive
1
To Receive

When switched to NB position the RF Noise
Blanker is activated, providing increased noise
filtration.
When switched to OFF position Noise
Blanking Filtration will be turned off.
Operation
Operation
NB, OFF
(Noise Blanker)
Switch
RF Gain Control
Bright/Dim
Switch
RF Gain Control
The RF Gain is used to optimize reception in
strong or weak signal areas.
Bright/Dim Switch
Not
The RF Gain is used to optimize
reception in weak signal areas.
Turn counterclockwise to reduce
gain.
Not
The RF noise blanker is very
effective in reducing repetitive
noises such as ignition interfer-
ence.
Switch to BRT or D M to control brightness
of the channel indicator and multi-function
meter for day or nighttime driving.
Rotate the RF Gain knob counterclockwise
to reduce gain in strong signal areas. n weak
signal areas turn clockwise to increase gain.
1
B, OFF ( oise Blanker) Switch
1
1

Full clockwise rotation closes the gate
allowing only very strong signals to enter.
Full counterclockwise rotation opens the
“gate” allowing all signals in.
To achieve the Desired Squelch Setting (DSS),
turn the Squelch control counterclockwise
until you hear noise. Now turn the control
clockwise just until the noise stops. This is the
DSS setting.
Setting Squelch
Squelch is the “control gate” for incoming signals.
Operation Operation
2
1
3
NOISE
WEAK SIGNALS
MEDIUM SIGNALS
STRONG SIGNALS

G AT E C L O S E D
NOISE
WEAK SIGNALS
MEDIUM SIGNALS
STRONG SIGNALS
NOISE
WEAK SIGNALS
MEDIUM SIGNALS
STRONG SIGNALS

G AT E 
OPEN
NOISE
WEAK SIGNALS
MEDIUM SIGNALS
STRONG SIGNALS

NOISE
WEAK SIGNALS
MEDIUM SIGNALS
STRONG SIGNALS
G AT E
Gat op n
Gat s t to D sir d
Squ lch S tting (DSS)
Gat clos d
Setting Squelch

Setting Dynamike®
This controls the microphone sensitivity
(outgoing audio level).
To Transmit
To Transmit
Setting
Dynamike®
Caution!
Be sure the antenna is properly
connected to the radio before
transmitting. Prolonged trans-
mitting without an antenna, or
a poorly matched antenna,
could cause damage to the
transmitter.
Be sure to read the F.C.C. Rules
and Regulations included with
this unit before transmitting.
Operation Operation
1
Select desired channel.
1
nitially, set fully clockwise so that maxi-
mum voice volume is available. Dynamike®
may have to be reduced in some conditions.
Transmit
Push and hold mic button to transmit.
Transmitter is now activated. When transmit-
ting, hold the microphone two inches from
your mouth and speak in a clear, normal voice.
Release to receive.
1
PUSH &
HOLD
Transmit
RF Meter
RF Meter
This meter swings proportionately to the RF
output (outgoing signal) while transmitting.

Operation
Operation
PA (Public
Address)
PA (Public Address)
Connect an external PA speaker to the PA jack
on the rear panel.
Not
Speaker should have 8-ohm
impedance and be rated to
handle at least 4.0 watts.
Not
The speaker should be directed
away from the microphone to
prevent acoustic feedback.
Not
When the volume control is
rotated clockwise, activity on
the CB channel will be heard
through the PA speaker.
1
Set CB/ANL PA switch to PA position.
2
External Speaker
External Speaker
The external Speaker jack is used for remote
receiver monitoring.
Not
The external speaker should
have 8-ohm impedance and be
rated to handle at least 4.0
watts. When the external speak-
er is plugged in, the internal
speaker is automatically discon-
nected.
Not
Cobra external speakers are
rated at 10 watts. Connect an external speaker to the external
speaker jack on the rear panel.
1

Temporary Mobile Set-Up
Operation
Temporary
Mobile Set-Up
Temporary Mobile Operation
For temporary mobile operation you may want to
purchase an optional cigar lighter adapter from
your COBRA dealer. This adapter and a magnetic
mount antenna allow you to quickly “install” your
transceiver for temporary use.
A L (Automatic oise Limiter) Switch
When switched to CB/ANL the Automatic
Noise Limiter is activated. This helps reduce
noise created by the vehicle’s electronics.
1
Push and hold microphone button and speak
in a normal voice. Your voice will sound on the
PA speaker.
Adjust PA speaker volume with the
Dynamike control.
3
4
PUSH &
HOLD

Home And Office Set-Up
Base Station
Operation
(From 120V AC
House Current)
Base Station Operation
(From 120V AC House Current)
To operate your transceiver from home or office
you will need a 13.8 volt DC Power Pack rated at a
minimum of 2 amps, and a properly installed
base station antenna.
Home And Office Set-Up
Warning!
Do not attempt to operate this
transceiver by connecting it
directly to 120 vac.
1
Connect properly installed and matched base
station antenna.
Simply connect the red (+) and black (-)
leads of the transceiver to the corresponding
terminals of the power pack.
Plug power cable into back of unit marked
“Power”. Be sure to observe polarity markings.
2
3