21LTDST.MANUAL.REV.QX 9/25/98 10:59 AM Page 1 OPERATING INSTRUCTIONS FOR YOUR 40 CHANNEL CITIZENS BAND 2-WAY MOBILE RADIO Model 21 LTD ST Cobra Electronics Corporation 6500 W. Cortland Street Chicago, IL 60707 PRINTED IN HONG KONG ©COBRAELECTRONICS CORP.
1LTDST.MANUAL.REV.QX 9/25/98 10:59 AM Page 3 How To Use Your The CB Story The Citizens Band lies between the shortwave broadcast and 10-meter Amateur radio bands, and was established by law in 1949. The Class D two-way communications service was opened in 1959. (CB also includes a Class A citizens band and Class C remote control frequencies.) FCC regulations permit only “transmissions” (one party to another) rather than “broadcasts” (to a wide audience).
21LTDST.MANUAL.REV.QX 9/25/98 10:59 AM Page 5 Specifications (cont.) Specifications FREQUENCY RANGE The COBRA21 LTD ST transceiver represents one of the most advanced AM twoway radios ever designed for use as a Class D station in the Citizens Radio Service. This unit features advanced Phase Lock Loop (PLL) circuitry providing complete coverage of all 40 channels as shown below. Channel Channel Frequency in MHz Channel Channel Frequency in MHz 1 2 3 4 5 26.965 26.975 26.985 27.005 27.
21LTDST.MANUAL.REV.QX 9/25/98 10:59 AM Page 7 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. Installation (Cont.) 3. Connect the antenna cable plug to the standard receptacle on the unit.
21LTDST.MANUAL.REV.QX 9/25/98 10:59 AM Page 9 Installation (Cont.) Installation (Cont.) CB Antenna Ignition Noise Interference 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.
21LTDST.MANUAL.REV.QX 9/25/98 10:59 AM Page 11 Operation Operation (Cont.) Controls and Indicators 6. RX/TX LED INDICATOR. When your radio is in the CB receive mode, the LED will be green. When in transmit mode, the LED will be red. 7. LED CHANNEL DISPLAY. The selected channel will be displayed. 8. CB-PA SWITCH: Selects the mode of operation. In the CB position, the PA function is disabled and the unit will transmit and receive on the selected frequency.
21LTDST.MANUAL.REV.QX 9/25/98 10:59 AM Page 13 Operation (Cont.) Operation (Cont.) B. Press-To-Talk Microphone Operating Procedure to Receive Both the receiver and transmitter are controlled by the Press-to-Talk switch on the microphone. Press the switch and the transmitter is activated; release the switch to receive. When transmitting, hold the microphone two inches from the mouth and speak clearly in a normal voice. The microphone provided with your radio is a detachable low-impedance dynamic type.
21LTDST.MANUAL.REV.QX 9/25/98 10:59 AM Page 15 Operation (Cont.) Operating Procedure to Transmit 1. Be sure the operator has read and understands part 95, F.C.C. Rules and Regulations prior to operating the transmitter. 2. Select the desired channel. 3. Set the DYNAMIKE control fully clockwise. 4. 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.
21LTDST.MANUAL.REV.QX 9/25/98 10:59 AM Page 17 Maintenance and Adjustment Appendix The 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.
21LTDST.MANUAL.REV.QX 9/25/98 10:59 AM Page 19 Appendix (Cont.) If You Think You Need Service A Few Rules That Should Be Obeyed 1. 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. If You Think You Need Service, Call 773-889-3087 “If your product should require factory service please call Cobra first before sending your unit in.
21LTDST.MANUAL.REV.QX 9/25/98 10:59 AM Page 21 Warranty and Service OPTIONAL ACCESSORIES You can find these fine accessories at your local Cobra CB dealer. Description Limited Two Year Warranty COBRAELECTRONICS CORPORATION warrants that its COBRAcitizens band (CB) radio, and the component parts thereof, will be free of defects in workmanship and materials for period of two (2) year from the date of first consumer purchase.
