Kenwood TK 940 Service Manual

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GENERAL INTRODUC'TION SCOPE OF THIS MANUAL ns are recommended for This manual i? intended for use by experienced v technicians familiar with similar types of commercial one is within two feet (0.6 grade communications equipment. It contains all re- quired service information for the equipment and is ransmit until all RF connectors are verified current as of the publication data. Changes which may ectors are properly termi- occur after publication are covered by either Service Bulletins or Manual Revisions. These are issued as re- DO NOT operate this equipment quired. lasting caps or in an explosive at- ORDERING REPLACEMENT PARTS properly grounded before When ordering replacement parts or equipment in- formation, the full part identification number should be erviced by a qualified technician only. included. This applies to all parts : components, kits, or chassis. If the part number is not known, include the chassis or kit number of which it is a part, and a suffi- cient description of the required component for proper identification. PRE-INSTALLATION CONSIDERATIONS 1. UNPACKING Unpack the radio from its shipping container and check for accessory items. If any item is missing, please contact KENWOOD immediately. 2. LICENSING REQUIREMENTS Federal regulations require a station license for each radio installation (mobile or base) be obtained by the equipment owner. The licensee .is responsible for en- ring transmitter power, frequency, and deviation are hin the limits permitted by the station license. ansmitter adjustments may be performed only by nsed technician holding an FCC first, second or ss commercial radiotelephone operator's li- re is no license required to install or operate FCC COMPLIANCE AND TYPE NUMBERS 3. PRE-INSTALLATION CHECKOUT 3-1. Introduction Each rad~o IS adjusted and tested before shipment. However, it is recommended that recerver and trans- mitter operation be checked for proper operatron be- fore ~nstallat~on. 3-2. Testing The radio should be tested complete with all cabl~ng and accessories as they wrll be connected In the f~nal installatron. Transmrtter frequency, dev~at~on, and power p~tput should be checked, as should recelver ~gn~jtivity, squelch operation, and audio output, 'Q~~equiprnent operation should be verif~ed. Complrance Part 90 Part 90 Type acceptance number ALHTK-940-1 ALHTK-941-1 Frequency range 806-870MHz 896-941 MHz

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9401941 E INSTALLATION 5. INSTALLATION PLANNING - CONTROL STATIONS 5-1. Antenna system e vehicle and determine how and where Control station. The antenna system seect~on de- pends on many factors and IS beyond the scope of this cable runs for protection against pinching or manual. Your KENWOOD dealer can help you select g wiring, and radio installation to prevent,over- an antenna system that will best serve your particular needs. 4-2. Antenna 5-2. Radio location The favored location for an antenna Is In the center Select a convenlent location for your control stat~on of a large, flat conduct~ve area, usually at the roof ten- rad~o which is as close as practical to the antenna cable ter The trunk Ild IS preferred, bond the trunk and entry pornt Secondly, use your system's power supply vehicle chassis using ground straps to ensure the Ild 1s (whlch supplles the voltage and current requ~red for at chassis ground your system) Make sure suff~c~ent air can flow around the rad~o and power supply to allow adequate cool~ng 4-3. Radio The universal mount bracket allows the radio to be mounted in a variety of ways. Be sure the mounting surface is adequate to support the radio's weight. Al- low sufficient space around the radio for air cooling. Position the radio close enough to the vehicle operator to permit easy access to the controls when driving. 4-4. DC Power and wiring 1 Th~s rad~o may be ~nstalled In negatlve ground eec- tr~cal systems only Reverse polar~ty will cause the f cable fuse to blow Check the veh~cle ground polar- I ~ty before ~nstallat~on to prevent wasted time and 1 effort k 2 Connect the posltive power lead d~rectly to the ve- t i h~cle battery pos~tive term~nal Connect~ng the Posi- t tive lead to any other posltlve voltage source In the I. veh~cle IS not recommended F If DC power is to be controlled by the vehicle ign~tion 1 """"" switch, a switching relay should be used to switch the / posltwe power lead The vehcle ignition switch then 1 controls DC to the relay co~l I 1 3 Connect the ground lead d~rectly to the battery negatlve termlnal 4 The cable prov~ded wlth the radlo IS suff~c~ent to handle the maximum radio current demand If the cable must be extended, be sure the addit~onal wire IS suff~c~ent for the current to be carr~ed and length of the added lead SERVICE This radio is designed for easy servicing. Refer to the schematic diagrams, printed circuit board views, and alignment procedures contained in this manual. Note When you modify your radio as described in systern set-up, take the following precaution. The rating of pin 7 (SB) of the accessory connector cable (KCT-19) on the rear of the radio is 13.6V (IA). Insert a 1A fuse if you use the SB pin for external equipment. Accessory connector cable (KCT-19) Fuse (IA) If you do not intend to use the 3.5-mm jack for the external speaker, fit the supplied speaker-jack cap (B09-0235-XX) to stop dust and sand getting in. Speaker-jack cap (B09-0235-XX)

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OPERATING FEATURES . GROUP key 5-2. Panel Tuning Mode Used to select the signal~ng encodeldecode data or This mode can be inhibited by programming. The squelch adjustment. following can be adjusted with the front keys: Squelch level Table 2 down for two more seconds. The display changes from "TUNING" to "800MHz" (TK-940) or "900NIHzU (TK- QT fine deviation . DQT fine deviation LTR ID fine deviation RF power DQT balance Maximum deviation Frequency (TX) The mode is entered when the GROUP DOWN key - GROUP 1 2 3 4 5 6 7 8 941), and then back to the systemlgroup number AUX key indication. When the AUX key is pressed, talk-around is Select the frequency to be adjusted by pressing the enabled (the "TAN indicator appears), and transmission SYSTENI key when the systemlgroup number is being is possible on the receive frequency. When the key is displayed, then press the SCAN key. Adjustment pressed again, talk-around is disabled. mode is entered and the adjustment level can be * Area : 0. Goto : 12, Home . 12, ID : 47, Free : 25 is held down, the power turned on, and the key kept TONE None (No decode; squelch can be adjusted.) -- 100H: sqilare wave (No decode; squelch can be adjusted ) ---- LTR format' (Decode; squelch cannot be adjusted.) QT (67,OHz) (Decode; Squelch cannot be adjusted..) QT (1 51.4Hz) (Decode; squelch cannot be adjusted.) QT (210.7Hz) (Decode; squelch cannot be adjusted.) DQT (023N) (No decode; squelch cannot be adjusted.) DOT (754N) (No decode; squelch cannot be adjusted.) Fj varied between 1 to 256. 1 SCAN key When this key is pressed, the squelch is turned off. SYSTEM key If a carrier is not present, white noise is heard. The Used to select the frequency or items to be "BUSY indicator appears. adjusted Transmission The microphone PTT key is used to start GROLIP key Used to select signaling encodeldecode data or the transmission. When the frequency and signaling have . adjustment level. been selected wirh the SYSTEM and GROUP keys, transmission begins and the "TX" indicator appears. AUX key The time-out-timer does not work. Used to determine the adjustment level. Select the level with the GROUP key and then press the AUX key. The adjustment level is written into the internal serial EEPROM. SCAN key Used to sw~tch between adjustment frequency variable mode and adjustment level (item) mode. Volume key Used to vary the volume or adjust the AF power level.