Kenwood TH-77A Service Manual

144/440(430)MHz FM DUAL BANDER
TH-77A/E
SERVICE MANUAL
KENWOOD
©1990-8 PRINTED IN JAPAN
B51-8057-00(B)1105
———— CONTENTS
DISASSEMBLY FOR REPAIR.........:cscssceccscssssesesesseessseessvess 2
CIRCUIT DESCRIPTION ...ccscccsscsccssesssseecesecsesesseessesenseensssee 4
DESCRIPTION OF COMPONENTS. ......cccescccscsesssseecsseeeene 16
SEMICONDUCTOR DATA. ......cccsscssssescecseccescessesssecrecsersese 20
PARTS LIST....ccsccsscsocscscssecsssescsssccsseessseeees B e ete tee 29
Antenna DISASSEMBLY ............0...ccccccecccssccessesssceescecsesenseseeccceneneees 48
(790-0414-05) PAGKING 250. ei.cs0cg:hs accaceligseralisedsiuvitdessangdaoucaseverbicecseeteor 49
ADJUSTMENT .......cssccssssssccssecccscsccsscsssececsecsusceracsnseesncessese 50
PC BOARD VIEWS/CIRCUIT DIAGRAMS
-% VHF VCO (X58-3740-00) ...ccssscsucccossccessececsrsnscneesnecsrseecses 55
bi nen Wvar) UHF VCO (X58-3760-00)..-cssssscsovessssesossevssssscersessessecocesss 56
| (K29-4570-04)x2 APC 1K502077 0-00) (AVS itect aks ots ce canes 57
| be PI, (H5B597.70-0G) 1B) cscavtasceetsdesescssaestanoeetasncivtencbtehes 58
SUB-U (X59-37 70-00): (Chsscacsercescctevadvivervesissnasnasosavsersie 59
Knob (ENCODER) NOISE AMP (X58-3770-00) (D).ccccsecccesssseecsseccessseecneeereee 60
ie Neo aeee 4) AM (X59-3810-00) (B) ..ssssscsssssssesscsvecessecaressnessescneecenesssse 61
Knob (SQL) . f B00 MHz (X59-3810-00) (A) .sessssssssesecesecesessscsseersessssensees 62
(K29-4571-04) ee
eet
CONTROL UNIT (X53-333X-XX)..ssssesceeeessssseeseessceseeneeees 63
Pee TX-RX UNIT (X57-3630-XX) (REV) .vscesssseeersvesseestsesseeeses 67
| TX-RX UNIT (X57-3630-XX) (RFU) .scsccessecsesccsecsecersseessves 69
SCHEMATIC DIAGRAM u....ccsscssscsecccsssscsecsseseuseseecacceeseesee 71
BLOCK DIAGRAM......cscssscsssessssscscsseccsessesecstesrsesseenssesseesses 77
——" ee lee cores LEVEL DIAGRAM.................cccccccccereeseccecceccssessccceececerseesees 79
-0975-03): K , P , M , TERMINAL FUNCTIONS ..0....ccsscssssscscccesssecssssessesssssseenseess 81
ep a ie BC-9 (BATTERY CHARGER) ..ccccccccsssscssscccsssssssssceveeessooe 82
BT-6 (AAA MANGANESE/ALKALINE BATTERY CASE) ................. 82
BC-10 (COMPACT CHARGER).........cccscsesessssescesssssessesssees 83
cis i BC-11 (RAPID CHARGER) .........cccccscsscsosecsescssesceccucsseereees 84
wu DC-4/5 (MOBILE CHARGER)............ccscsceccscssesseceueeseesseres 89
BC-12 (WALL CHARGER)........cccscsssssccsesesesssssessesssessseenees 89
HMC-2 (HEAD SET WITH VOX & PTT) ...scscsssessssessesssees 90
Battery ass'y
HS-7/8/9 (EAR PHONE) ............::cccsccsecceeeeesecssteeneenseeesenens 92
PB-5/6/7/8 (Ni-Cd BATTERY) .....sccsscsscesecsssccctsesssssseessses 93
PB-9/10 (Ni-Cd BATTERY) ....c.ccssccoscssecesecseecssscasssccsseeseess 94
PG-2W (DC CORD)/PG-3F (CORD WITH PLUG)............ 95
SC-28/29 (SOFT CASE) ...cccccessscsessssssscececsessscsesseecasessecesess 96
WR-1 (WATERPROOF CASE) .......cccscscececesssssccseecesecsesssees 96
SMC-31/32 (SPEAKER MICROPHONE) ...........:++e-02e000++- 97
Photo is TH-77A.
SMC-33 (SPEAKER MICROPHONE).........0...ccssecsssssseesoee 98
eter to parts list on page 29. TSU-7 (CTCSS UNIT) cesccssccsssssccssssssssessssccsssesscsssseeeeveee 99
SPECIFICATIONS. .........ccsssessssssseeeetessseeeceees BACK COVER