Kenwood TK-785 Service Manual

Also see for TK-785: Instruction manual

2TK-785 GENERALINTRODUCTIONSCOPE OF THIS MANUALThis manual is intended for use by experienced techni-cians familiar with similar types of commercial grade com-munications equipment. It contains all required service in-formation for the equipment and is current as of the publica-tion data. Changes which may occur after publication arecovered by either Service Bulletins or Manual Revisions.These are issued as required.ORDERING REPLACEMENT PARTSWhen ordering replacement parts or equipment informa-tion, the full part identification number should be included.This applies to all parts : components, kits, or chassis. If thepart number is not known, include the chassis or kit numberof which it is a part, and a sufficient description of the re-quired component for proper identification.PERSONNEL SAFETYThe following precautions are recommended for person-nel safety :• DO NOT transmit if someone is within two feet (0.6meter) of the antenna.• DO NOT transmit until all RF connectors are verified se-cure and any open connectors are properly terminated.• SHUT OFF and DO NOT operate this equipment nearelectrical blasting caps or in an explosive atmosphere.• All equipment should be properly grounded beforepower-up for safe operation.• This equipment should be serviced by a qualified techni-cian only.PRE-INSTALLATION CONSIDERNATIONS1. UNPACKINGUnpack the radio from its shipping container and checkfor accessory items. If any item is missing, please contactKENWOOD immediately.2. PRE-INSTALLATION CHECKOUT2-1. IntroductionEach radio is adjusted and tested before shipment. How-ever, it is recommended that receiver and transmitter op-eration be checked for proper operation before installation.2-2. TestingThe radio should be tested complete with all cabling andaccessories as they will be connected in the final installa-tion. Transmitter frequency, deviation, and power outputshould be checked, as should receiver sensitivity, squelchoperation, and audio output. QT equipment operationshould be verified.3. PLANNING THE INSTALLATION3-1. GeneralInspect the vehicle and determine how and where theradio antenna and accessories will be mounted.Plan cable runs for protection against pinching or crush-ing wiring, and radio installation to prevent overheating.3-2. AntennaThe favored location for an antenna is in the center of alarge, flat conductive area, usually at the roof center. Thetrunk lid is preferred, bond the trunk lid and vehicle chassisusing ground straps to ensure the lid is at chassis ground.3-3. RadioThe universal mount bracket allows the radio to bemounted in a variety of ways. Be sure the mounting surfaceis adequate to support the radio’s weight. Allow sufficientspace around the radio for air cooling. Position the radioclose enough to the vehicle operator to permit easy accessto the controls when driving.3-4. DC Power and wiring1. This radio may be installed in negative ground electricalsystems only. Reverse polarity will cause the cable fuseto blow. Check the vehicle ground polarity before installa-tion to prevent wasted time and effort.2. Connect the positive power lead directly to the vehiclebattery positive terminal. Connecting the Positive lead toany other positive voltage source in the vehicle is not rec-ommended.3. Connect the ground lead directly to the battery negativeterminal.4. The cable provided with the radio is sufficient to handlethe maximum radio current demand. If the cable must beextended, be sure the additional wire is sufficient for thecurrent to be carried and length of the added lead.