Conventional FM TWO-WAY Radio | EFJohnson 764X, 761X specification

761x (VHF)

764x (UHF)

CONVENTIONAL

FM TWO-WAY RADIO

VHF 146-174 MHz

45 Watts

UHF 400-430, 450-470, 470-490, or 490-512 MHz

35 Watts

Copyright© 1998 by Transcrypt International Incorporated

Transcrypt offers communication solutions in two core areas: land mobile radio products and systems, and information security. EFJohnson land mobile radios and systems pro- vides wireless communication for a variety of markets including government, public safety, and commercial users. Transcrypt’s information security devices utilize sophisticated scrambling and encryption techniques to protect sensitive voice and data transmissions.

Viking Head/EFJohnson logo and Call Guard® are registered trademarks of Transcrypt International Incorporated. Smartrunk II™ is a trademark of Smartrunk Systems Inc. All other company and/or product names used in this manual are trademarks and/or regis- tered trademarks of their respective manufacturer.

Information in this manual is subject to change without notice.

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EFJohnson 764X, 761X service manual Conventional FM TWO-WAY Radio

Contents

761x VHF 764x UHF Conventional Mobile Conventional FM TWO-WAY Radio Table of Contents Table of Contents CONT’D Schematic Diagrams and Component Layouts General Information Toll-Free 800 75xx AccessoriesAccessory Factory Returns Replacement Parts Internet Home This page intentionally left blank VHF and 7640 UHF Mobile Specifications General General Information Installation and Disassembly Transceiver Installation Power Cable Installation Installing Mounting BracketInstalling Microphone Hanger Cable Installation Using AN External Speaker Power Cable FusesChanging 20-Ampere Power Cable Fuses Accessory Cable Installation Remove shield E Transceiver DisassemblyRemoving PC Board Setting 5-Tone Deviation 2-TONE/5-TONE Module InstallationInstallation Procedure 2 2-TONE Programming Installation and Disassembly Features Operation Basic Operation Controls and DisplayTransceiver Back Panel Direct Selection The F1-F4 Receiving and Placing Calls Option Key Programmable Functions TIME-OUT TimerProgrammable Functions Function Key Label Description Section No Call Guard Tone Select Monitor Mode SelectOutput Power Select Channel Select Channel Scan Priority Channel Sampling Programming Cables Programming SetupSection Programming Programming Software Menu Flow Starting the ProgramSpecial Keys and Functions File Menu Print Menu Screen MenuProgram Menu Model Menu Parameter Description Bank Select Setup MenuMemory Channel Screen Description LMR Models Frequency TimerCh Atr Rx/Tx Scan Auto ResetLockout Tone Key and Display Assign Screen Description Key Description Key Description Label Selection RF PowerDtmf Autodial Screen Description Bank/Free Parameter Description Continuous Tone Screen DescriptionScan Function Screen Description Resume Stop Timer2-Tone Code Channel Screen Description Auto CH Auto Tx EXO TimerTimer Auto Tx Stun Common Screen Description Expert Screen Description Unique PMR European Screens Unique PMR Screens Cloning Programming ONE Transceiver with Another Memory Channel Screen PMR Models This page intentionally left blank VHF 7610 Circuit Description VHF Receiver Circuit Audio Amplifier Circuit Receiver Mute Circuit Microphone Amplifier Circuit Power Amplifier ModuleVHF Transmitter Circuit Modulation Circuit PLL Circuit APC CircuitVHF PLL Circuit Pin Port Description VHF IC PIN DescriptionsLine Description VHF Port Expander IC11 Main Unit VHF I/O Expander IC5 Main UnitPin Pin Port Description Name UHF 7640 Circuit Description UHF Receiver Circuit Second if System IC1 UHF UHF Transmitter Circuit PLL Circuit UHF UHF PLL Circuit UHF Power Supply UHF CPU IC1 Port Allocation UHF I/O Expander IC12 Main Unit UHF Port Expander IC13 Main Unit Suggested Test Equipment Adjustment ProcedureTest Setup Equipment Grade and Range Test Channels Test Cable UHF Test Frequencies COMPUTER-AIDED TuningVHF Test Frequencies Preliminary Setup VHF AdjustmentsVHF Adjustments PLL Adjustment VHF Models FM Deviation Adjust VHF Adjustments CONT’DOutput Power Adjust Bandpass Filter Adjust Dtcs Waveform AdjustReceiver Adjustments VHF Models Squelch Adjust Beep Tone Level Adjustment Beep Tone Level Transmitter Adjustments UHF Models UHF AdjustmentsPLL Adjustment UHF Models UHF Adjustments CONT’D UHF Adjustment Points UHF Adjustments CONT’D Receiver Adjustments UHF Models Parts List Æçìíýõ9+ôý0$,1ý81,7 Íäç HUDPLFý&ìçíåý-%ýì+ýìíë.ð7ð$ Íëëðêäíçðíçí Íäæ Ìää HUDPLFý&ìçíåý-%ýì&ýìíé.7ð1 Íëëðêäíçðçìé Ëíí Ëäí HUDPLFý&ìçíåý-%ýìýìíê.ð7ð$ Íëëðêäíçðíçê Ëäì RLOý0/ìçíå$ýì5í.ð7 Íëëðêäíçðçèç 03ì Ýìäëëý9&2ýFDVH 5íéé 5HVý5-ê*-ýìííý9ýõìíýRKPô Íëëðêäíçðìêå 5íéè 5ìèé 5HVý5-ê*-ýìíéý9ýõìííýNýRKPô Æçéíýõ8+ôý0$,1ý81,7 Íêì HUDPLFý&ìçíåý-%ýì+ýìíë.ð7ð$ Íëëðêäíçðíçí Íêë Íäé HUDPLFý+0çí6-ý&+ýíêíýèíí9ý Õéäíðèìëý0+ô Ìèì 5HIý1Rï Êëç Íëëðêäíçðäèë 4éì 7UDQVLVWRUý7&êçê.ý7ìéæ 5íæé 5ìçå 5HVý5-ê*-ýìíéý9ýõìííýNýRKPô 5217ý81,7 Õ9+ý$1ý8+ý02/6ô =HQHUý0$åíèìð0ýõ7ô Æçìíýõ9+ôý&+$66,6ý3$576 VHF 7610 Exploded View Front Unit UHF 7640 Exploded View Main Unit Schematic Diagrams and Component LayoutsVHF 7610 Block Diagram Front Unit VHF 7610 Transistor Basing Diagrams Foldout → VHF 7610 Main Board TOP View VHF 7610 Main Board Schematic VHF Main Unit UHF 7640 Block Diagram UHF 7640 Main Board Bottom View UHF 7640 Main Board TOP View J4 T o O p tion al Un it UHF 7640 Main Board Schematic VHF/UHF Front Unit Board TOP View VHF/UHF Front Unit Board Bottom View VHF/UHF Front Unit Schematic UHF 7640 Transistor Basing Diagrams