Realistic dx 302 service manual

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CONTENTS
CONTROLS AND THEIR FUNCTIONS ................. I . . . .. .......................... 3
V SPECIFICATIONS .............................................................. 4-5
PRINCIPLES OF OPERATION ........ , .............................. ................... 6
BLOCK DIAGRAM ..................... 2 ........................................... 7
OPERATION CHECK/ALIGNMENT PREPARATION ..................................... 8
AF OPERATION CHECK ....................... _ .................................... 9
2ND/3RD IF OPERATION CHECK .................................... _ ............... 9
1ST IF OPERATION CHECK ................................. ........................ I o
IST LOCAL OSC OPERATION CHECK ........ I ........... , ............................. 11
2ND LOCAL FREO. AMP OPERATION CHECK .......................................... 11
TOTAL GAIN CHECK ........................................................... 12- 13
PRESELECTOR DIAL CALIBRATION ............ . ................ . ................... 14
LINKAGE ADJUSTMENT OF MHz SWITCH ............................................ 14
3RD IF ALIGNMENT .............................................................. 14
ALIGNMENT OF kHz TRACKING .................................................... 15
2ND IF ALIGNMENT .............................................................. 16
CRYSTAL FREQUENCY ALIGNMENT ................................................ 16
ALIGNMENT OF 2ND LOCAL FREO. AMP ............................................. I7
IST IF ALIGNMENT ............................................................... 18
IST LOCAL OSC ALIGNMENT ...................................... . ................ 19
RF STAGE ALIGNMENT ........................................ '. . .; ............... 2o
BFO ALIGNMENT ............................................................. 21
S-METER ALIGNMENT ............................................................ 21
TROUBLESHOOTING GUIDE ................................................... 22 - 23
RF PC. BOARD, TOP VIEW ......................................................... 24
RF P.C. BOARD, BOTTOM VIEW ..................................................... ' 25
IF/AF PC. BOARD, TOP VIEW ....................................................... 26
IF/AF P.C. BOARD, BOTTOM VIEW .................. . ............................... 27
ATT. P.C. BOARD, TOP VIEW ........................................................ 28
ATT. P.C. BOARD, BOTTOM VIEW ......... . ......................................... 28
COUNTER PC. BOARD, TOP VIEW ................................................... 29
COUNTER PC. BOARD, BOTTOM VIEW ..................................... ., ......... 29
MHz SWITCH P.C. BOARD, TOP VIEW... ..................................... > ......... 3 0
MHz SWITCH P.C. BOARD, BOTTOM VIEW ..... ... ............... 2., .................. 30
PRESELECTOR COIL P.C. BOARD, TOP'VIEW .......... . .......... , L. . ........ . ........ 31
PRESELECTOR COIL P.C. BOARD, BOTTOM VIEW ................ T. ............. . ...... 31
MHz PC. BOARD, TOP VIEW ........................................... . ............ 31
MHz PC. BOARD, BOTTOM VIEW ................ . . ................ .' ................. 31
WIRING DIAGRAM (TOP) .......................................................... 32
WIRING DIAGRAM (BOTTOM) .......................... .. . . ................ » ..... 33
ELECTRICAL PARTS LIST ... ................ ._... ..... . ...... , ......... . ........ 34 - 4o
MECHANICAL PARTS LIST ...................................................... 41 - 43
ACCSESSO RY LIST ............................................................... 43
APPENDIX TO PARTS LIST ......................................................... 43
INTEGRATED CIRCUIT IDENTIFICATION ......................................... 44 45
TRANSISTOR LEAD IDENTIFICATION ................................................. 45
SEMICONDUCTOR VOLTAGE READINGS ............................................ 4S
SCHEMATIC DIAGRAM OF DIGITAL FREO. READOUT SECTION ................. . ....... 47
SCHEMATIC DIAGRAM ......................................................... 48-- 49
DISASSEMBLY/EXPLODED VIEW ................. ..._ ............................ 50- 51

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