Pioneer f 28 service manual

Page 2

MODEL F-28 COMES IN TWO VERSIONS DISTINGUISHED AS FOLLOWS:

Typo Voltlga Remarks
KU 120V only U.S.A. model
SIG 110V, 120V, 220V, 240V (Switchable) U.S. Military model

This service manual is applicable to the KU type. When repairing the SIG type, please see

the additional service manual (P.53 to P.67).

CONTENTS
1. SPECIFICATIONS ..................... 3
2. FRONT PANEL FACILITIES ............. 4
3. BLOCK DIAGRAM .................... 5
4. CIRCUIT DESCRIPTIONS
4.1 Signal Circuit ..................... 5
4.2 PLL Synthesizer Circuit .............. 8
4.3 Control Circuit ................... 11
4.4 Power Supply Circuit ............... 15
5. DISASSEMBLY ....................... 16
6. PARTS LOCATIONS
6.1 Front Panel View .................. 18
6.2 Front View with Panel Removed ........ 18
6.3 Top View ....................... 19
6.4 Rear Panel View ................... 19
7. DIAL CORD STRINGING ................ 20
8. ADJUSTMENTS
8.1 Synthesizer Assembly ............... 21
8.2 FM Front End .................... 22
8.3 IF Assembly ..................... 23
8.4 MPX AF Assembly ................. 25
9. PACKING ........................... 26

1D. EXPLODED VIEWS
10.1 ,External Parts .................... 27
10.2 Internal Parts .................... 29

11. SCHEMATIC DIAGRAMS, P.C. BOARD
PATTERNS AND PARTS LIST

11.1 Miscellanea ...................... 31
11.2 Schematic Diagram ................. 33
11.3 P.C. Board Connection Diagram ........ 37
11.4 FM Front-end (AWE-036) ............. 41
11.5 Switch Assembly A (GWS~141) ......... 42
11.6 Switch Assembly B (GWS142) ......... 42
11.7 IF Assembly (AWE-097i ............. 43
11.8 Power Supply. Assembly (AWR-177) ..... 46
11.9 Synthesizer Assembly (AWX-146) ....... 47
11.10 MPX AF Assembly lAWD-O14) ......... 49
11.11 Lamp Assembly (AWX-132) ........... 52
Additional Service Manual
1. CONTRAST OF MISCELLANEOUS PARTS . . . 54
2. SUPPLEMENTS FOR S/G TYPE
2.1 Schematic Diagram ................. 55
2.2 Power Supply Assembly (AWRv178) ..... 63
2.3 Switch Assembly (AWX-147) .......... 64
2.4 MPX AF Assembly (AWD-OIS) ......... 65