Cobra 29ltd Stcb Tranciever Manual
Have a look at the manual Cobra 29ltd Stcb Tranciever Manual online for free. It’s possible to download the document as PDF or print. UserManuals.tech offer 42 Cobra manuals and user’s guides for free. Share the user manual or guide on Facebook, Twitter or Google+.
OPERATING INSTRUCTIONS FOR YOUR 40 CHANNEL CITIZENS BAND 2-WAY MOBILE RADIO Model 29 LTD ST Cobra Electronics Corporation 6500 W. Cortland Street Chicago, IL 60707 PRINTED IN HONG KONG ©COBRA ELECTRONICS CORP. 1997 480-113-P-001
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 commu- nications service was opened in 1959. (CB also includes a Class Acitizens band and Class C remote control frequencies.) FCC regulations permit only ÒtransmissionsÓ (one party to another) rather than ÒbroadcastsÓ (to a wide audience). Thus, advertising is not allowed on CB Channels because that is Òbroadcasting.Ó “Cuts Static coming in, adds Punch going out!” Cobra proudly introduces the first Patent Pending technology that dramatically improves the transmission and reception of CB radio signals. This revolutionary system reconfigures the transmission signal which allows it to be transferred more effectively through cluttered airwaves. It literally ÒpunchesÓ your message through the hundreds of thousands of signals that are in the air. At the same time, SoundTracker system dynamically adjusts the relationship between the signal and static commonly referred to as noise. This allows CobraÕs SoundTrackersystem to significantly reduce the amount of static on all incoming CB signals. The system can be further optimized when two SoundTracker CBÕs are used to talk to each other. The end result is a clearer, cleaner sounding reception of signals and more powerful transmissions which dramaticallyimprove CB Communications Serial No.Date of PurchaseDealer Name Keep this manual for detailed information about your Cobra CB radio. SAVE YOUR SALES RECEIPT, THE CARTON AND “PACKING” FOR POSSIBLE FUTURE USE. All transmitter adjustments other than those supplied by the manufacturer as front panel operating controls, must be made by, or under the supervision of, the holder of an FCC-issued general Radio-Telephone OperatorÕs License. Replacement or substitution of transistors, regular diodes or other parts of a unique nature, with parts other than those recommended by Cobra, may cause violation of the technical regulations of Part 95 of the FCC Rules, or violation of Type Acceptance requirements of Part 2 of the Rules. You should read and understand Part 95 (included with this unit) of the FCC Rules and Regulations, before operating your Cobra radio, even though the FCC no longer requires you to obtain an operators license. The CB Story 1 How To Use YourCitizens Band 2-Way Mobile RadioModel 29 LTD ST ContentsPage The CB Story............................................................................................1 SoundTracker System............................................................................1 Specifications........................................................................................2,3 Installation Location..................................................................................................4 Mounting 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....................................................12 How SoundTracker Works................................................................13 Maintenance and Adjustment............................................................14 Appendix Ten Code..............................................................................................15 AFew Rules That Should Be Obeyed............................................16 How Your CB Can Serve You..........................................................16 Warranty Service Instructions............................................................17 Limited Two Year Warranty................................................................18 Accessories..................................................................Inside Back Cover
Specifications (cont.) GENERALChannels40 Frequency Range26.965 to 27.405 MHz. Frequency ControlPhase Lock Loop (PLL) synthesizer. Frequency Tolerance0.005%. Operating Temperature Range-30¡C to + 50¡C. MicrophonePlug-in dynamic. Input Voltage13.8VDC nom.(positive or negative ground). Current DrainTransmit: AM full mod., 1.5A(maximum) Receive: Squelched, 0.3A; full audio output, 1.2A (nominal). Size8 5 / 8Ó D x 79 / 32Ó W x 2 13 / 64Ó H . Weight4 lbs. Antenna ConnectorUHF, SO-239. Semiconductors26 transistors, 26 diodes, 4 integrated circuits. Meter Illuminated; indicates relative power output and received signal strength.TRANSMITTERPower Output4 watts. ModulationAM (Amplitude Modulation). Frequency Response300 to 3000 Hz. Output Impedance50 ohms, unbalanced.RECEIVERSensitivityLess than 1 µV for 10dB (S+N)/N. Selectivity6dB @ 7 KHz, 60 dB @ 10 KHz. Image Rejection 80 dB, typical. Adjacent-Channel Rejection60 dB, typical. IF FrequenciesDouble Conversion: 1st: 10.695 MHz. 2nd: 455 KHz. Automatic Gain Control (AGC)Less than 10 dB change in audio output for inputs from 10 to 50,000 microvolts. RF Gain ControlAdjustable for optimum signal reception. Noise BlankerRF type. SquelchAdjustable; threshold less than 1µV. Audio Output Power4 watts. Frequency Response300 to 3000 Hz. DistortionLess than 7% @ 3 watts @ 1000 Hz. Built-in Speaker16 ohms, round. External Speaker (Not Supplied)8 ohms; disables internal speaker when connected.PASYSTEMPower Output4 watts into external speaker. External Speaker for PA8 ohms, when PA-CB switch is in PA, the PAspeaker also monitors the receiver; separate jack provided. (SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE) (Not Supplied) 3 ChannelChannel Frequency in MHz 2127.215 2227.225 2327.255 2427.235 2527.245 2627.265 2727.275 2827.285 2927.295 3027.305 3127.315 3227.325 3327.335 3427.345 3527.355 3627.365 3727.375 3827.385 3927.395 4027.405 Specifications FREQUENCYRANGE The COBRA29 LTD ST transceiver represents one of the most advanced AM two-way 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. ChannelChannel Frequency in MHz 126.965 226.975 326.985 427.005 527.015 627.025 727.035 827.055 927.065 1027.075 1127.085 1227.105 1327.115 1427.125 1527.135 1627.155 1727.165 1827.175 1927.185 2027.205 The COBRA29 LTD ST has a vastly superior receiver which includes noise blanker circuitry and an automatic noise limiter. The receiver also features increased protection against cross modulation and strong adjacent channel signals. To obtain maximum performance please read carefully the descriptions and operating instructions in this manual. Fill out below; keep for your records.Serial No. Date of Purchase Dealer Name Keep this manual for detailed information about your Cobra CB radio. SAVE YOUR SALES RECEIPT, CARTON AND PACKING FOR POSSIBLE FUTURE USE. 2
5 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 +13.8 VDC. In automobile instal- lations, +13.8 VDC 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 vehicles engine running. Before installing the CB radio, visually check the vehicle battery connec- tions 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 he black lead to the negative side of the automobile. This is usual- ly the chassis of the car. Any convenient location with good electrical con- tact (remove paint) may be used. Plug power cable into jack on back of transceiver. In positive ground automobiles the red wire goes to the chassis and the black wire is connected to the ignition switch. 6. Mount 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. Installation Location Plan the location of the transceiver and microphone bracket before starting the in- stallation. 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 and Connection The transceiver is held in the universal mounting bracket by two thumbscrews, permitting adjustment at the most convenient angle. Auniversal 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
7 Installation (Cont.) 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 and therefore will not significantly discharge the vehicle bat- tery. Even though the COBRA29 LTD ST has an automatic noise limiter, in some in- stallations ignition interference may be high enough to make good communica- tions impossible. The electrical noise may come from several sources. Many pos- sibilities exist and variations between vehicles require different solutions to reduce the noise. Consult your COBRAdealer 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 12 VDC power pack that has been specially designed for the purpose. It is available as optional equipment from your COBRAdealer. It consists of a 120-volt, 60 Hz AC to 12-volt DC power converter that delivers the required power for the operation of the transceiver. 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. Temporary Mobile Operation To operate your COBRAtransceiver from a car on a temporary basis, you may want to purchase an optional cigar lighter adapter from your COBRAdealer. This adapter and a magnetic mount antenna allow you to quickly install your transceiver for temporary use. 6 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. Avertically polarized, quarter-wavelength whip antenna provides the most reli- able operation and greatest range. 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 di- rection of the body of the vehicle. For all practical purposes, however, the radia- tion pattern is nondirectional. The slight directional characteristic will be observed only at extreme distances. Astandard antenna connector (type SO-239) is provided on the transceiver for easy connection to a standard PL259 cable termination. 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 customer representative. WX Antenna For best reception of weather channels, we recommend dual band antennas which provide optimum CB and WX reception. If you want more information about models and prices, call our consumer hotline 773-889-3087. When installed in a boat, the transceiver will not operate at maximum efficien- cy 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 Combination 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. The quality of reception of radio signals is highly dependent on the antenna sys- tem. Typical CB antennas may not be very efficient when used for WX recep- tion. Call 773-889-3087 for further information. Installation (Cont.)
Operation (Cont.) 9 6. DELTA-TUNE.For normal operation, set this control to the center posi- tion. This feature has several uses and can greatly enhance receiver oper- ation. If a received signal is slightly off frequency, the Delta-Tune control can be used to Òfine-tuneÓ your receiver. Fine tuning is accomplished by listening for a more readable signal at the speaker or by noting the S- meter reading when the Delta-Tune control is operated. Another use of this control is eliminating adjacent interference. If an exceptionally high level signal from an adjacent channel is creating inter- ference on the channel being used, the Delta-Tune can be used to mini- mize or eliminate the interference. Rotate the control until you obtain minimum adjacent channel interference. NOTE:Delta-Tune is operable only in the receivemode. 7.SWR CAL. Used to calibrate the meter for SWR (standing wave ratio) measurements. Simply switch to CAL, press the PTT switch on the microphone and calibrate the meter.8.CHANNELSELECTOR SWITCH.This switch selects any one of forty Citizens Band channels desired. The selected channel is indicated by the LED readout (18), directly above the channel selector knob.9.S/RF/SWR/CALSWITCH.When in the S/RF position, the meter swings proportionally to the strength of the received signal. When transmitting, the meter indicates relative RF output power. When in the CAL position, the SWR meter can be calibrated by adjust- ing the SWR CAL control to the CAL mark on the meter face. When in the SWR position, the standing wave ratio is measured.10 .NB-ANL/ANL/ OFFSWITCH:When this switch is in the ANLposition, only the automatic noise limiter in the audio circuits is activated. When it is in the NB/ANLposition, the RF noise blanker also is activated. The RF noise blanker is very effective for repetitive impulse noise, such as igni- tion interference. 11 .PA/CBSWITCH:.Selects the mode of operation. In the CB position, the PAfunction is disabled and the unit will transmit and receive on the selected frequency. The PAfunction should not be used unless a PAspeaker is connected. In the PAmode, incoming CB transmissions will be heard through the PAspeaker. This allows you to monitor messages when you are not inside your vehicle. 12 .BRT/DIM SWITCH:Controls brightness of the LED channel indicator (18) and the multi-function meter (14), for optimum intensity for day or nighttime driving. Controls and Indicators Refer to controls, indicators and connectors as illustrated below: A. Front Panel 1. MICROPHONE CONNECTOR.Front panel microphone connector. 2. OFF/ON/VOLUME.Turn clockwise to turn power on and set the desired listening volume. 3. SQUELCH.This control is used to cut off or eliminate receiver back- ground noise in the absence of an incoming signal. For maximum receiv- er 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. 4. DYNAMIKE.Adjusts the microphone gain in the transmit and PA modes. This controls the gain to the extent that full talk power is avail- able several inches away from the microphone. In the Public Address (PA) mode, the control functions as the volume control. 5. RF GAIN.Adjust as required to optimize signal. This control is used pri- marily to optimize reception in strong signal areas. Gain is reduced by counterclockwise rotation of the control. Operation 8 11 12 14 16 17 18 15 13 1 2 3 4 5 6 8 9 10 7
Operation (Cont.) 11 C. Rear Panel1. PUBLIC ADDRESS:An external 8-ohm 4.0 watt PAspeaker may be connect- ed to the PASpeaker 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 PAat high output levels. 2. EXTERNALSPEAKER: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 inter- nal speaker is automatically disconnected. 3. ANTENNACONNECTOR:This SO-239 connector permits connection of the transmission line cable PL-259 connector to the transceiver. 4. POWER. This jack permits connection of the DC power to the transceiver. A power cord with polarized plug is supplied with the radio. The polarized plug ensures that the power will always be connected properly. 1 2 3 4 13. CH.19/CH.9/NORMALSWITCH. Used for instant selection of emer- gency Channel 9 (CH. 9 position) or information Channel 19. In NOR- MALposition, all 40 CB channels are selected by the CHANNELSELEC- TOR switch (8). 14. S-METER. Swings proportionally to the strength of the incoming signal during receiving. The S/RF-SWR-CALswitch must be in the S/RF position. RF-METER.Swings proportionally to the RF output power while trans- mitting. The S/RF-SWR-CALswitch must be in the S/RF position. SWR METER.Measures standing wave ratio of the antenna system. Used to properly adjust the length of the antenna and to monitor the quality of the coaxial cable and all RF electrical connections. If there is any degradation whatsoever in any of the foregoing, due to humidity, salt spray, vibration or corrosion, the SWR meter reading will rise, thereby indicating that a problem exists. To calibrate, switch to the CAL position, transmit by pressing the mike switch, and adjust the SWR control to the CAL mark on the meter; then switch to SWR position for the SWR measurement. 15 .RX/TX LEDINDICATOR.When your radio is in the CB receive mode, the LED will be green. When in transmit mode, the LED will be red. 16. SOUNDTRACKER™ SWITCH.Depressing this button turns on the SoundTracker system in your CB. 17. SOUNDTRACKER™ INDICATOR.Ared LED will illuminate when the SoundTracker system is engaged on your CB. 18. LED CHANNELDISPLAY.The selected channel will be displayed. B. PRESS-TO-TALK MICROPHONE.Both the receiver and transmitter are con- trolled 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. Operation (Cont.) 10
13 12 Operation (Cont.) Operating Procedure to Receive 1. Be sure that the power cord, antenna and microphone are connected to the proper connectors before proceeding further. The PA/CB should be in the CB position. 2. Turn the radio ON by rotating the VOLUME CONTROLclockwise. 3. Set the RF GAIN CONTROLfully clockwise. 4. Set DELTA-TUNE CONTROLto center(click-stop) position. 5. Rotate SQUELCH CONTROLcounterclockwise until incoming signal is heard. 6. Set the CHANNELSELECTORSwitch to the desired channel. 7. Set VOLUME CONTROLto a comfortable listening level. 8. Engage the SoundTracker system by depressing the buttons labeled ST. Listen to the background noise from the speaker. Turn the SQUELCH CON- TROLslowly clockwise until the noise JUSTdisappears (no signal should be present). Leave the control at this setting. The squelch is now properly adjust- ed. 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. The revolutionary SoundTracker system allows you to reduce unwanted back- ground noise (static) and increase the signal for better reception. 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 pr ess-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 clearly in a 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 PAspeaker to the PAjack provided on the rear panel. 2. Place PA/CB/ANLswitch into the PAposition. 3. Depress push-to-talk switch on micÑspeak in normal voice. 4. Adjust PAspeaker volume with front panel DYNAMIKE control. When the Volume control is rotated clockwise, activity on the CB channel will be heard through the PAspeaker. How SoundTracker Works SOUNDTRACKER SYSTEMWhile previous systems only Òblanked outÓ or limited noise in higher sound frequencies, the revolutionary new SoundTracker System actually reduces noise while leaving the signal intact in the reception 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 SOUNDTRACKER WORKSOn Reception– “Cuts Noise Coming In” With a normal CB, distant signals fall below the squelch level and are unintelligi- ble. With a SoundTracker CB, the noise level is cut by 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.On Transmission– “Strengthens Signals Going Out” ASoundTracker 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.
15 14 Maintenance and Adjustment The COBRACB transceiver is specifically designed for the environment encoun- tered 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. 1.Check connections to the source of power and make sure it is the 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 3AG type fuse in its holder. 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:COBRAantennas include full instructions as to how to tune your antenna. If youre still in doubt about the procedure, contact the COBRAdealer from whom you purchased your radio and antenna, for advice. If you hired an installer to install your radio and antenna, contact the installer. If you are unable to correct the problem, refer the WARRANTYSERVICE INSTRUCTIONS at the end of this manual for the correct procedure for warran- ty and post-warranty service from COBRA. Adjustment Warning Replacement or substitution of certain parts with replacements other than those recommended by COBRA, may be a violation of the technical regulations of Part 95 of the FCC Rules, or of Type Acceptance requirements of Part 2 of said rules. When making adjustments other than transmitter adjustments, be sure to re- read applicable portions of this instruction manual to make certain you are fol- lowing correct procedure and that the radio was properly installed, etc. For technical assistance, please call our Automated Help Desk which can assist you by answering the most frequently asked questions about Cobra products. (773) 889-3087 24 hours a day, 7 days a week. AConsumer Service Representative can be reached through this same number 8:00 am - 8:00 pm, Monday through Friday, CST. Technical assistance is also available on-line in the Frequently Asked Question (FAQ) section at www.cobraelec.com or by e-mail to [email protected] 10-35Confidential information 10-36Correct time is 10-37Wrecker needed at 10-38Ambulance needed at 10-39Your message delivered 10-41Please turn to channel 10-42Traffic accident at 10-43Traffic Tie up at 10-44I have a message for you 10-45All units within range please report 10-50Break channel 10-60What is next message number? 10-62Unable to copy, use phone 10-63Net directed to 10-64Net clear 10-65Awaiting your next message/assignment 10-67All units copy 10-70Fire at 10-71Proceed with transmission in sequence 10-77Negative contact 10-81Reserve hotel room for 10-82Reserve room for 10-84My telephone number is 10-85My address is 10-91Talk closer to mike 10-93Check my frequency on this channel 10-94Please give me a long count 10-99Mission completed, all units secure 10-200Police needed at Appendix Citizens Band radio operators have largely adopted the Ò10-codeÓ for standard questions and answers. Its use permits faster communications and better under- standing in noisy areas. The following table lists some of the more common codes and their meanings: CodeMeaningCodeMeaning 10-1Receiving poorly 10-2Receiving well 10-3Stop transmitting 10-4OK, message received 10-5Relay message 10-6Busy, stand by 10-7Out of service, leaving air 10-8In service, subject to call 10-9Repeat message 10-10Transmission completed, standing by 10-11Talking too rapidly 10-12Visitors present 10-13Advise Weather/Road conditions 10-16Make pick up at 10-17Urgent business 10-18Anything for us? 10-19Nothing for you, return to base 10-20My location is 10-21Call by telephone 10-22Report in person to 10-23Stand by 10-24Completed last assignment 10-25Can you contact 10-26Disregard last information 10-27I am moving to channel 10-28Identify your station 10-29Time is up for contact 10-30Does not conform to FCC rules 10-32I will give you a radio check 10-33EMERGENCYTRAFFIC 10-34Trouble at this station