EFJohnson 764X - Manual (Page 5)

TABLE OF CONTENTS (CONT’D)
iv
November 1998
Part No. 001-7600-001
8 SCHEMATIC 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