Cobra Cobra 25 NW ST User manual

How to Use Your
Cobra 25 NW ST
Contents
Features...........................................................................................1
The CB Story..................................................................................A1
FCC Regulations
FCCWarnings
Included Accessories
Controls & Indicators................................................................A2
OurThanks to You......................................................................A3
SoundTracker™
Customer Support
Installation
Location.......................................................................................2
Mounting and Connection...................................................2
Antennas
CB Antenna................................................................................6
Marine Installation...................................................................6
Ignition Noise Interference...................................................7
Operating Your 25 NW ST
Turning On Your CB.................................................................8
Setting Channel Selector.......................................................9
To Receive...................................................................................10
Selecting a Channel................................................................10
S-Meter.........................................................................................11
SoundTracker™System.........................................................12
Activating SoundTracker™..................................................13
Dimmer Control........................................................................14
RF Gain Control.........................................................................14
Setting Squelch.........................................................................15
ToTransmit.................................................................................17
Setting Dynamike....................................................................18
Transmit.......................................................................................19
RF Meter......................................................................................19
External Speaker.......................................................................20
PA (Public Address)..................................................................21
ANL (Automatic Noise Limiter) Switch.............................23
NB,OFF (Noise Blanker) Switch...........................................23
Temporary Mobile Set-Up.....................................................24
Home And Office Set-Up.......................................................25
How Your CB Can Serve You...................................................27
A Few Rules You Should Know............................................27
Channel 9 Emergency Messages.......................................27
CB 10 Codes...............................................................................29
Frequency Ranges......................................................................31
25 NW ST Specifications..........................................................32
Warranty Information ..............................................................33
Optional Accessories.................................................................34
Order Form ....................................................................................36
If You Think You Need Service .............................Back Cover
FeaturesofThis Product
• 40CBRadio Channels
• SoundTracker™System
• Heavy-DutyDynamic
Microphone
• Full4WattsAMRFPowerOutput
• InstantChannel19 and9
• FrontPanel 4-PinMicrophone
Connector
• SwitchableNoise Blanker
• SwitchableAutomatic
NoiseLimiter
• AdjustableDynamike Boost
• TactileControls
• IlluminatedFrontPanel
• DimmerControl
• RFGain
• 9ft.miccord
1
CAUTION: TO REDUCE THE RISK OF ELECTRIC
SHOCK DO NOT REMOVE COVER (OR BACK)
NO USER SERVICEABLE PARTS INSIDE
REFER SERVICING TO QUALIFIED SERVICE
PERSONNEL
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN !!
25 NWST Manual3.3 6/15/99 12:43 PM Page 1

InstallationInstallation
Location
32
Mounting and
Connection
Mounting and Connection
Hold the radio with the mounting bracket in
the exact desired location.If 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 interferewith the driver or passenger.
The transceiver is usually mounted to the under-
side of the dash with the microphone bracket
beside it.
Note
Thetransceiveris heldin the
universalmountingbracket by
twothumbscrews whichallow
foradjustmentat aconvenient
angle.
Thebracketincludes twoself-
tappingscrewsand starwash-
ers.Themountingmustbe
mechanicallystrong,conve-
nientlylocated.
continued
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
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InstallationInstallation
54
Note
Beforeinstalling the CBradio,
visuallycheck the vehicle’s
batteryconnection to deter-
minewhich terminal, positive
ornegative,isgrounded (pos-
itiveis the largerofthetwo)
to theengine block(or chas-
sis).A negatively grounded
vehiclehasitsnegative lead
groundedto the chassis.
Note
Connectingtoan accessoryfuse
preventstheunit frombeing left
onaccidentally,andalsoper-
mitsoperatingthe unitwithout
runningtheengine.
Note
Inpositiveground vehiclesthe
redwiregoes tothe chassisand
theblackwire isconnectedto
theignitionswitch.
In 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
Attach the 4-pin microphone cable to recepta-
cle on front of unit and Install unit in bracket
securely.
8
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Ignition Noise InterferenceAntennas
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 back-
ground 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 signifi-
cantly discharge the vehicle’s battery.
Even though the Cobra 25 NW ST has an auto-
matic 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.
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.
Marine Installation
The transceiver will not operate at maximum effi-
ciency 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.
CB Antenna
7
Note
Foroptimumperformancein
passengercarsthe idealanten-
nalocationison thecenterof
theroof.Secondchoiceisonthe
centerofthe trunk.
Note
Becausemanynewertrucks
featurefiberglassdoor skins,the
outsidemirrormust beground-
edtothe chassisvia aground
strap,ifthe antennais mounted
onthemirror bracket.
Note
3-wayCombinationAntennas
arealsoavailablewhichallow
operationofall threebands
(AM-FM & CB),using a single
antenna.However,thistypeof
antennausuallyresults inless
thannormaltransmit and
receiverangewhen compared
toastandard-type“Single
Band”CBantenna.Call
773.889.3087forfurther infor-
mation.
6
1A standard antenna connector is provided
on the transceiver for easy connection.
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The CB/PA button should be in the
CB position.
Operation
9
Operation
Turning On Setting Channel
Selector
8
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 clockwiseto
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
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Rotate the On/OffVolume knob clockwise
the green RT/TX LED will be illiuminated.
Operation
11
Operation
10
S-Meter
S-Meter
Swings proportionately to strength of incoming
signal when receiving.
Switch to NOR to select desired channel.
1
Selecting A
Channel
Selecting A Channel
Note
Switchto 9(Emergency) or19
(Information)forinstant access
tothesechannels.
To Receive
1
To Receive
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OperationOperation
1312
Activating
SoundTracker
™
Pushandrelease the ST button.Red LED
is illuminated when SoundTracker™ is
turned on.
1
The SoundTrackerTM System
While previous systems only “blanket out”or limit
noise in higher sound frequencies, the revolution-
ary new SoundTrackerTM System actually reduces
noise while leaving the signal intact in the recep-
tion mode. In the transmission mode, it actually
strengthens the signal,providing you with a
significant reduction in noise on reception
and transmission.
Sound clarity is measured by the ratio
of the signal level to the noise level.
The higher the signal-to-noise ratio,
the better the sound.
How SoundTrackerTM Works
OnReception-“Cutsnoise comingin”
With a normal CB,distant signals fall below
the squelch level and are unintelligible.With a
SoundTrackerTM CB,the noise level is cut up to
90%,which increases the signal-to-noise ratio
and dramatically improves signal clarity.This also
allows you to significantly reduce the squelch
level,which greatly expands your listening range.
OnTransmission-“Strengthenssignalsgoingout”
A SoundTrackerTM CB strengthens the transmit
signal by more effectively using the available RF
power output of the CB.The result is improved
transmission signal clarity and an expanded
transmission range.
Note
SoundTracker™givesyou
clearer,cleanerreceptionto
improveCB communications
whileonthe air.
Activating SoundTracker™
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OperationOperation
1514
RF Gain Control
Dimmer Control
RF Gain Control
The RF Gain is used to optimize reception in
strong or weak signal areas.
Dimmer Control
Note
TheRFGain isusedtooptimize
receptioninweak signalareas.
Rotate the DIM knob clockwise for
maximum brightness;counter-clockwise
for minimum.
Rotate the RF Gain knob counterclockwise
to reduce gain in strong signal areas. In weak
signal areas turn clockwise to increase gain.
1
1
Note
TheDimcontrols thebrightness
of the front panel,signal strength
meterandchannel display.
Gateopen
Gate closed
Setting Squelch
Full clockwise rotation closes the gate
allowing only very strong signals to enter.
Full counterclockwise rotation opens the
“gate”allowing all signals in.
Setting Squelch
Squelch is the “control gate”for incoming signals.
2
1
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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.
1716
Operation Operation
3
Gateset to Desired
Squelch Setting(DSS) ToTransmit
To Transmit
Caution!
Besurethe antennaisproperly
connectedtothe radiobefore
transmitting.Prolongedtrans-
mitting without an antenna,or
apoorlymatchedantenna,
couldcause damagetothe
transmitter.
Besuretoread theF.C.C.Rules
andRegulationsincluded with
thisunitbefore transmitting.
Select desired channel.
1
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Setting Dynamike
This controls the microphone sensitivity
(outgoing audio level).
1918
Setting
Dynamike
Operation Operation
1Initially,set fully clockwise so that maxi-
mum voice volume is available.Dynamike
may have to be reduced in some conditions.
Transmit
Pushand 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
Transmit
RF Meter
RF Meter
This meter swings proportionately to the RF
output (outgoing signal) while transmitting.
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