HOW TO USE YOUR
40 CHANNEL
CITIZENS BAND
2-WAY MOBILE RADIO
Model 19 DX
II
Nothing comes close to a Cobra™
PRINTED IN THAILAND
©2002 COBRA ELECTRONICS CORPORATION
6500 WEST CORTLAND STREET
CHICAGO, IL 60707 USA
480-045-P
HOW TO USE YOUR
Serial No.
Date of Purchase
Dealer Name
40 CHANNEL
Keep this manual for detailed information
about your Cobra CB Radio System.
SAVE YOUR SALES RECEIPT, THE
CARTON AND “PACKING” FOR
POSSIBLE FUTURE USE.
The Cobra® line of quality products includes:
CB radios
®
microTALK radios
Radar/Laser Detectors
GPS
®
Safety Alert
Traffic Warning Systems
Accessories
HighGear™ Accessories
If You Think You Need Service,
please contact your local dealer.
CITIZENS BAND
2-WAY MOBILE RADIO
Model 19 DX
II
Introduction
Frequency Range........................................................................................2
Specifications ..................................................................................................3
Installation
Location ......................................................................................................4
Mounting and Connections ..................................................................4-5
CB Antenna ................................................................................................6
Ignition Noise Interference ......................................................................7
Operation
Controls and Indicators ....................................................................8-9-10
Operating Procedure to Receive ............................................................11
Operating Procedure to Transmit ..........................................................11
Maintenance and Adjustment ....................................................................12
Appendix
Ten Code....................................................................................................13
A Few Rules That Should Be Obeyed ..................................................14
How Your CB Can Serve You ................................................................14
Use Channel 9 for Emergency Messages Only....................................15
Introduction
Specifications
Frequency Range
Your COBRA CB radio provides high-level, trouble-free performance
over the following frequency assignments:
Channel
Channel Frequency
in MHz
Channel
Channel Frequency
in MHz
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
26.965
26.975
26.985
27.005
27.015
27.025
27.035
27.055
27.065
27.075
27.085
27.105
27.115
27.125
27.135
27.155
27.165
27.175
27.185
27.205
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
27.215
27.225
27.255
27.235
27.245
27.265
27.275
27.285
27.295
27.305
27.315
27.325
27.335
27.345
27.355
27.365
27.375
27.385
27.395
27.405
These frequencies are generated and accurately controlled by a phase
lock hoop (PLL) circuit, comprised of the latest state-of-the-art
integrated circuit technology, ensuring high reliability and excellent
frequency stability on the above channels.
To obtain maximum performance please read carefully the
descriptions and operating instructions in this manual.
2
GENERAL
Channels
Frequency Range
Frequency Control
Frequency Tolerance
Operating Temp. Range
Microphone
Input Voltage
Current Drain
Size
Weight
Antenna Connector
Semiconductors
Meter
TRANSMITTER
Power Output
Modulation
Frequency
Output Impedance
Output Protection
RECEIVER
Sensitivity
Selectivity
Image Rejection
Adjacent CH. Rejection
IF Frequencies
40.
26.965 to 27.405 MHz.
Phase-Locked Loop (PLL) synthesizer.
0.005%.
-22°F to +122°F (-30°C to +50°C).
Plug-in type; Electret condenser.
13.8V DC nom. (negative ground).
Transmit: AM full mod., 1.5A (maximum).
Receive: (Squelched, 0.115A, full audio
output 1.0A (nominal).
6-5/8”D x 4-9/16”W x 1-13/16”H
(165mm x 116 mm x 44 mm.)
3 lbs., 4 oz. (1.0 kg.).
UHF, SO-239.
22 transistors, 17 diodes, 3 integrated
circuits, 7 LEDs.
Indicates relative power output and
received signal strength.
4 watts.
High- and low-level Class B amplitude.
300 to 3000 Hz.
50 ohms, unbalanced.
Output transistors protected against
mismatch up to 20:1.
Less than 1µV for 10dB(S + N)/N.
6 dB @ 7 KHz, 55dB @ 15 KHz.
60 dB typical.
50 dB, typical.
Double conversion, 1st: 10.695 MHz.
2nd: 455 KHz.
Less than 10dB change in audio output for
inputs from 10 to 50,000µV.
Adjustable; threshold less than 1µV.
3 watts.
300-3000 Hz.
Less than 10% @ 3 watts @ 1000 Hz.
8 ohms, round.
8 ohms; disables internal speaker when
connected.
Automatic Gain Control
(AGC)
Squelch
Audio Output Power
Frequency Response
Distortion
Built-in Speaker
External Speaker
(Not Supplied)
PA SYSTEM
Power Output
4 watts into external speaker.
External Speaker for PA
8 ohms; a separate jack is provided.
(Not Supplied)
(Specifications subject to change without notice.)
3
Installation
Location
Plan the location of the transceiver and microphone bracket before
starting the installation. Select a location that is convenient for
operation and does not interfere with the driver or passengers in the
vehicle. In automobiles, the transceiver is usually mounted to the
underneath of the dash panel, with the microphone bracket beside it.
Mounting Connection
The transceiver is held in the universal mounting bracket by two
thumb screws, permitting adjustment at the most convenient angle.
A universal mounting bracket is supplied along with self tapping
screws and star washers. The mounting must be mechanically strong
and also provide a good electrical connection to the chassis of the
vehicle. To mount the transceiver:
1. Determine the most convenient location in your vehicle. Hold the
COBRA radio with mounting bracket in the exact location desired.
If nothing will interfere with mounting it in the desired position,
remove the mounting bracket and use it as a template to mark the
location for the mounting screws.
2. Drill necessary holes and secure mounting bracket in location.
4
Installation (Cont.)
3. Connect the antenna cable plug to the standard receptacle on the
unit. Most CB antennas are terminated with a type PL-259 plug
which mates with the receptacle marked “ANT.”
4. Connect the red lead of DC power cord to +13.8VDC. In
automobile installations, +13.8VDC is usually obtained from the
accessory contact in the fuse box. This prevents the set being left
on accidentally and also permits operating the unit without the
vehicle’s engine running.
Before installing the CB radio, visually check the vehicle
battery connections to determine which battery terminal,
positive or negative (positive is the larger of the two) is
grounded to the engine block (or chassis).
5. Connect the black lead to the negative side of the automobile.
This is usually the chassis of the car. Any convenient location with
good electrical contact (remove paint) may be used.
6. Mount the microphone bracket on right side of the transceiver, or
near it using two screws supplied. When mounting in an
automobile, place the bracket under the dash so the microphone is
readily accessible.
5
Installation (Cont.)
Installation(Cont.)
CB Antenna
Since the maximum allowable power output of the transmitter is
limited by the FCC, the antenna is one important factor affecting
transmission distance. Only a properly matched antenna system will
allow maximum power transfer from the 50-ohm transmission line to
the radiating element. In mobile installations (cars, trucks, boats, etc.),
an antenna system that is non-directional should be used.
Ignition Noise Interference
Use of a mobile receiver at low signal levels is normally limited by the
presence of electrical noise. The primary source of noise in automobile
installations is from the alternator and ignition system in the vehicle.
Under most operating conditions, 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 vehicle engine turned off. The unit requires very little
current an therefore will not significantly discharge the vehicle battery.
A vertically polarized, quarter-wavelength whip antenna provides the
most reliable operation and greatest range. The shorter, loaded-type
whip antennas are more attractive, compact and adequate for
applications where the maximum possible distance is not required.
Also, the loaded whips do not present the problems of height imposed
by a full quarter-wavelength whip.
Mobile whip antennas utilize the metal body of the vehicle as a
ground plane. When mounted at a corner of the vehicle they are
slightly directional, in the direction of the body of the vehicle. For all
practical purposes, however, the radiation pattern is nondirectional.
The slight directional characteristic will be observed only at extreme
distances. A standard antenna connector (type SO-239) is provided on
the transceiver for easy connection to a standard PL 259 cable
termination. Cobra loaded-type antenna models ATW-500, AT-55,
ATW-1000 and ATW-400 are highly recommended for most
installations. Consult your Cobra dealer for further details.
When installed in a boat, the transceiver will not operate at
maximum efficiency without a ground plate, unless the vessel has a
steel hull. Before installing the transceiver in a boat, consult your
dealer for information regarding an adequate grounding system and
prevention of electrolysis between fittings in the hull and water.
3-Way Combinations Antennas are available which allow operation
of all three bands (AM-FM & CB), using a single antenna. However,
use of this type of antenna usually results in less than normal
transmit and receive range when compared to a standard-type
“Single Band” antenna designed for CB only.
6
Even though the COBRA radio has an automatic noise limiter, in
some installations, ignition interference and other forms of automobile
generated noise may be high enough to make good communications
difficult. The electrical noise may come from several sources. Many
possibilities exist and variations between vehicles require different
solutions to reduce the noise. Consult your COBRA dealer or a 2-way
radio technician for help in locating and correcting the source of
severe noise.
Base Station Operation (Operation from 120VAC, House Current)
To operate your transceiver from your home or office, using the
regular house current as the power source, you will require a 12VDC
power pack that has been specially designed for the purpose. It is
available as optional equipment from your COBRA dealer. It consists
of a 120-volt, 60 Hz AC to 12-volt DC power converter with a 3A
rating. Simply connect the red (+) and black (-) leads of the transceiver
to the corresponding terminals of the power packs.
DO NOT ATTEMPT TO OPERATE THIS TRANSCEIVER BY
CONNECTING DIRECTLY TO 120 VAC. SERIOUS DAMAGE
WILL RESULT.
Temporary Mobile Operations
To operate your COBRA transceiver from a car on a temporary basis,
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.
7
Operation
Operation (Cont.)
Controls and Indicators
Refer to controls, indicators and connectors as illustrated below:
5.
CB/PA Switch. Selects mode of operation. In the CB position, the PA
function is disabled and the unit will transmit and receive on the
selected channel. The PA function should not be used unless a PA
speaker is connected.
6.
S-RF/Power Meter. Shows relative transmitter RF output power
and input signal strength when receiving. The five LED (Light
Emitting Diode) segments glow to indicate receive or transmit
activity.
7.
TX Indicator LED. This indicator will light red when in the
transmit mode.
8.
LED Channel Display. The selected operating channel will be
displayed here.
9.
Channel Selector Switch. When turned, this knob is used to
select any one of the forty citizens band channels desired.
6
5
4
7
8
9
3
1
2
A. Front Panel
1. Off/On/Volume. Turn clockwise to turn power on and set the
desired listening volume.
2. Squelch. This control is used to cut off or eliminate receiver
background noise in the absence of an incoming signal. For
maximum receiver sensitivity, it is desired that the control be
adjusted only to the point where the receiver background noise or
ambient background noise is eliminated. Adjust until the receiver
noise disappears. This will require the incoming signal to be
slightly stronger than the average receiver noise. Further clockwise
rotation will increase the threshold level which a signal must
overcome in order to be heard. Only strong signals will be heard at
a maximum clockwise setting.
For a “RAPID” change of channels, depress and hold the desired
button (up and down). This allows all 40 channels to be covered
in about 6 seconds.
Other Operation Features
•Automatic Noise Limiter. This is a non-switchable feature that
is always on to reduce background noise.
3. Microphone Connector. This front mounted, screw-on connector
allows for convenient removal of the microphone plug when
storage is required. The microphone MUST be connected to the
unit at all times when in use, for proper operation. The screw-on
connection enhances the life of the microphone cord as well.
4. Channel 9/Normal Switch. Used for instant selection of
emergency channel 9 (CH 9 position). In NOR position, all 40 CB
channels are selected by the UP/DOWN CHANNEL BUTTONS.
8
9
Operation (Cont.)
2
Operation (Cont.)
1.
3
Operating Procedure to Receive
Be sure that the power, antenna and microphone are properly
connected before proceeding further. The CB/PA switch should be
in the CB mode. The Channel 9/NOR Switch should be in the
NOR mode.
2. Turn the radio ON by rotating the VOLUME CONTROL
clockwise.
3. Rotate SQUELCH CONTROL counterclockwise until incoming
signal is heard.
1
4
4. Turn the CHANNEL SELECTOR KNOB to select the desired
operating channel.
B. Rear Panel
1. ANTENNA CONNECTOR: This SO-239 connector permits
connection of the transmission line cable male connector to the
transceiver.
2. PUBLIC ADDRESS: An external 8-ohm 4.0 watt PA speaker may be
connected to the PA Speaker Jack when this unit is used as a public
address system. The speaker should be directed away from the
microphone to prevent acoustic feed-back. Physical separation or
isolation of the microphone and speaker must be employed when
operating the PA at high output levels.
3. EXTERNAL SPEAKER: The External Speaker Jack is used for
remote receiver monitoring. The external speaker should have
8-ohm impedance and be rated to handle at least 4.0 watts. When
the external speaker is plugged in, the internal speaker is
automatically disconnected.
4. POWER: These wires supply power to the CB radio. See page 5 for
installation.
5. Set the VOLUME CONTROL to a comfortable listening level.
Listen to the background noise from the speaker. Turn the SQUELCH
CONTROL slowly clockwise until the noise JUST disappears (no
signal should be present). Leave the control at this setting. The
squelch is now properly adjusted. The receiver will remain quiet until
a signal is actually received. Do not advance the control too far, or
some of the weaker signals will not be heard.
Operating Procedure to Transmit
1. Select the desired channel.
2. Press-to-Talk Switch. The receiver and transmitter are controlled
by the press-to-talk switch on the microphone. Press the switch
and the transmitter is activated; release switch to receive. When
transmitting, (on a clear channel), hold the microphone two inches
from the mouth and speak in a clearly normal voice.
Be sure the antenna is properly connected to the radio before
transmitting. Prolonged transmitting without an antenna, or a
poorly matched antenna, could cause damage to the transmitter.
Operating Procedure for Public Address
1. Connect a PA speaker to the PA jack provided on the rear panel.
2. Set the CB/PA switch to the PA position.
3. Depress the push-to-talk switch on the microphone and speak in a
normal voice.
4. Adjust the volume of the PA speaker using the Volume control on
the front panel.
10
11
Maintenance and Adjustment
Appendix
Your COBRA CB transceiver is specifically designed for the
environment encountered in mobile installations. The use of all solid
state circuitry and its light weight result in high reliability. Should a
failure occur, however, review the following, then if necessary replace
parts only with identical parts. Do not substitute. Refer to the
schematic diagram and parts list.
Citizens Band radio operators have largely adopted the “10-code”
for standard questions and answers. Its use permits faster
communications and better understanding in noisy areas. The
following table lists some of the more common codes and their
meanings:
10-CODE
1. Check connections to the source of power and make sure it is the
Code
10-1
10-2
10-3
10-4
10-5
10-6
10-7
10-8
10-9
10-10
13.8 VDC required to operate your radio.
2. Check the fuse in the DC power cord. The main power lead (red
wire) has a 2 Amp 3 AG type fuse installed. Use only the above
specified type and size fuse for maximum protection. Failure to do
so, will void the warranty.
3. Make certain the microphone is properly plugged in.
4. Make certain the antenna is properly connected and tuned for
minimum SWR. NOTE: COBRA antennas include full instructions
for tuning your antenna. If you’re still in doubt about the
procedure, contact the COBRA dealer from whom you purchased
your radio and antenna, for advice. If you hired an installer to
install your radio and antenna, contact him.
If you are unable to correct the problem, please contact your local
dealer.
Adjustment Warning
When making adjustments other than transmitter adjustments, be sure
to re-read applicable portions of this instruction manual to make
certain you are following correct procedure and that the radio was
properly installed, etc.
12
Meaning
Receiving poorly
Receiving well
Stop transmitting
OK, message received
Relay message
Busy, stand by
Out of service, leaving air
In service, subject to call
Repeat message
Transmission completed,
standing by
10-11 Talking too rapidly
10-12 Visitors present
10-13
10-16
10-17
10-18
10-19
10-20
10-21
10-22
10-23
10-24
10-25
10-26
10-27
10-28
10-29
10-30
10-32
10-33
10-34
Code
10-35
10-36
10-37
10-38
10-39
10-41
10-42
10-43
10-44
10-45
Meaning
Confidential information
Correct time is
Wrecker needed at
Ambulance needed at
Your message delivered
Please turn to channel
Traffic accident at
Traffic Tie up at
I have a message for you
All units within range
please report
10-50 Break channel
10-60 What is next message
number?
Advise Weather/Band
10-62 Unable to copy, use phone
conditions
10-63 Net directed to
Make pick up at
10-64 Net Clear
Urgent business
10-65 Awaiting your next
Anything for us?
message/assignment
Nothing for you, return
10-67 All units comply
to base
10-70 Fire at
My location is
10-71 Proceed with transmission
Call by telephone
in sequence
Report in person to
10-77 Negative contact
Stand by
10-81 Reserve hotel room for
Completed last assignment
10-82 Reserve room for
Can you contact
10-84 My telephone number is
Disregard last information
10-85 My address is
I am moving to channel
10-91 Talk closer to mike
Identify your station
10-93 Check my frequency on
Time is up for contact
this channel
Does not conform to FCC rules10-94 Please give me a long count
I will give you a radio check 10-99 Mission completed, all
EMERGENCY TRAFFIC
units secure
Trouble at this station
10-200 Police needed at
13
Appendix (Cont.)
1.
2.
3.
4.
5.
6.
•
•
•
•
•
•
•
•
•
A Few Rules That Should Be Obeyed
You are not allowed to carry on a conversation with another station for
more than five minutes at a time without taking a one-minute break, to
give others a chance to use the channel.
You are not allowed to blast others off the air by overpowering
them with illegally amplified transmitter power, or illegally high
antennas.
You can't use CB to promote illegal activities.
You are not allowed to use profanity.
You may not play music in your CB.
You may not use your CB to sell merchandise or professional
service.
How Your CB Can Serve You
Warn of traffic tie-ups ahead.
Provide weather and road information.
Provide help fast in event of emergency or breakdown.
Suggest good spots to eat and sleep.
Make long trips more interesting, and help keep you awake.
Provide direct contact with your office or home.
Make friends for you as you travel.
Provide "local information" to find your destination.
Help law enforcement officers by reporting drunk and reckless drivers.
14
Appendix (Cont.)
Use Channel 9 For Emergency Message Only
FCC give the following examples of permitted and prohibited types of
communications for use on Channel 9. These are guidelines and are
not intended to be all-inclusive:
Permitted:
Example Message:
Yes
”A tornado sighted six miles (10 km) north of town.”
No
”This is observation post number 10. No tornado
sighted.”
Yes
”I am out of gas on Interstate 95 at mile marker 121.”
No
”I am out of gas in my driveway.”
Yes
“There is a four-car collision at Exit 10 on the Beltway,
send police and ambulance.“
No
“Traffic is moving smoothly on the Beltway.“
Yes
”Base to Unit 1, the Weather Bureau has just issued a
thunderstorm warning. Bring the sailboat into port.”
No
“Attention all motorists. The Weather Bureau advises
that the snow tomorrow will accumulate 4 to 6 inches
(10 to 15 cm).”
Yes
“There is a fire in the building on the corner of 6th and
Main Streets.“
No
”This is Halloween patrol unit number 3. Everything is
quiet here.”
15