EFJohnson 761X, 764X service manual Schematic Diagrams and Component Layouts

TABLE OF CONTENTS (CONT’D)

8SCHEMATIC DIAGRAMS AND COMPONENT LAYOUTS

	VHF (761x) Models
	Block Diagram	. . .8-1
	Transistor and Diode Basing	. . .8-2
	Main Unit Board Bottom View	. . .8-3
	Main Unit Board, Top View	. . .8-4
	Main Unit Schematic	. . .8-5
	Front Unit PC Board	. .8-10
	Front Unit Schematic	. .8-11
	UHF (764x) Models
	Block Diagram	. . .8-6
	Transistor and Diode Basing	. .8-12
	Main Unit Board Bottom View	. . .8-7
	Main Unit Board, Top View	. . .8-8
	Main Unit Schematic	. . .8-9
	Front Unit PC Board	. .8-10
	Front Unit Schematic	. .8-11
	LIST OF TABLES
1-1	75xx Accessories	. . .1-2
3-1 Option Key Programmable Functions		. . .3-5
4-1 Memory Channel Screen Description
	(LMR Models)	. . .4-4
4-2 Key and Display Assign Screen Description		. . .4-7
4-3 DTMF Autodial Screen Description		. . .4-9
4-4 Continuous Tone Screen Description		. .4-10
4-5 Scan Function Screen Description		. .4-10
4-6	2-Tone Code Channel Screen Description . . . .4-11
4-7	Common Screen Description	. .4-13
4-8	Expert Screen Description	. .4-14
6-1	VHF Test Frequencies	. . .6-3
6-2	UHF Test Frequencies	. . .6-3

LIST OF FIGURES

2-1	Installation Components	2-1
2-2	Mounting Bracket Installation	2-2
2-3	Accessory Cable Installation	2-3
2-4 Cover and Front Panel Removal		2-4
2-5	PC Board Screws	2-4
2-6	Removing PC Board	2-4
2-7	2/5-Tone Module Installation	2-5
3-1	7600 Front Panel	3-1
4-1	Programming Setup	4-1
4-2 Memory Channel Screen (PMR Models) . . . .		4-17
5-1 Second IF System IC3 (VHF)		5-2
5-2 Audio Switching and Amplifier Circuit (VHF)		5-2
5-3	PLL Circuit (VHF)	5-4
5-4 Second IF System IC1 (UHF)		5-8
5-5 Audio Switching and Amplifier Circuit (UHF)		5-8
5-6	PLL Circuit (UHF)	5-10
6-1	Test Setup	6-1
6-2	Screen Display Example	6-2
6-3	Test Cable Schematic	6-2
6-4	VHF Adjustment Points	6-5
6-5 Beep Tone Level Adjustment		6-7
6-6	UHF Adjustment Points	6-9

November 1998
Part No. 001-7600-001	iv