Kenwood TH-K2AT, K2E, K2ET manual

144MHz FM TRANSCEIVER

TH-K2AT/K2E/K2ET

SERVICE MANUAL

© 2003-8 PRINTED IN JAPAN B51-8658-00 (S) 836

Helical Antenna				Helical Antenna
Helical Antenna				Helical Antenna
(T90-1018-25)				(T90-1018-25)

Knob (ENC)	Knob (ENC)
(K29-5159-03)	(K29-5159-03)

	Knob (VOL)		Knob (VOL)
	(K29-5150-03)		(K29-5150-03)
	Front glass		Front glass
Knob	(B10-2746-03)	Knob	(B10-2746-03)
(PTT/LAMP/MON)		(PTT/LAMP/MON)
(K29-9274-03)	Cap	(K29-9274-03)	Cap
	Cap		Cap
	(SP/MIC/DC IN)		(SP/MIC/DC IN)
	(B09-0675-03)		(B09-0675-03)
	Cabinet assy		Cabinet assy
	(16key)	Key top (4key)	(4key)
	(A02-3819-23)	Key top (4key)	(A02-3818-23)
		(K29-9276-02)

Key top (16key) (K29-9272-02)

TH-K2AT/K2ETTH-K2E

CONTENTS

DISASSEMBLY FOR REPAIR ...................................	2
CIRCUIT DESCRIPTION ............................................	6
SEMICONDUCTOR DATA ......................................	14
COMPONENTS DESCRIPTION ..............................	15
PARTS LIST .............................................................	17
EXPLODED VIEW ....................................................	23
PACKING .................................................................	25
ADJUSTMENT ........................................................	27
TERMINAL FUNCTION ...........................................	43
PC BOARD
TX-RX UNIT (X57-674X-XX) (A/3) ...................	44
TX-RX UNIT (X57-674X-XX) (B/3),(C/3) ..........	48


SCHEMATIC DIAGRAM ..........................................		50
LEVEL DIAGRAM ....................................................		55
BLOCK DIAGRAM ...................................................		56
BC-21 (WALL CHARGER) .......................................		58
PB-43N (Ni-MH BATTERY PACK) ..........................		58
BT-14 (BATTERY CASE) .........................................		59
PG-4Y (PROGRAMMING INTERFACE CABLE) .....		59
MCP-1A (MEMORY CONTROL PROGRAM) .........		59
SPECIFICATIONS .................................	BACK COVER

Contents

PC BOARD TX-RXUNIT (X57-674X-XX)(A/3) TX-RXUNIT (X57-674X-XX)(B/3),(C/3) PB-43N (Ni-MHBATTERY PACK) PG-4Y(PROGRAMMING INTERFACE CABLE) ■Numeric key PC board (TX-RXunit B/3) ■ PTT PC board (TX-RXunit C/3) ■TX-RXPC board (TX-RXunit A/3) Page 1. Gluing to the key top (MIC element section) Fig 2.Bending the LCD hardware fixture (J21-8456-03)tabs 3. PTT PCB (TX-RXunit C/3) installation procedure 4.Packing (G53-1572-02)TX/BUSY lamp installation procedure 6.Cautions for installing the chassis on the case assembly 5.Packing (G53-1572-02)bottom installation procedure 7.Cautions for installing the key top on the case assembly Table 1 Basic configuration ■Front End ■First Mixer Table 2 MCF (L71-0619-05)characteristics (TX-RXunit XF1) Fig. 2 Receiver section configuration ■IF Circuit ■Squelch and Mute Circuit ■S Meter Circuit Fig. 3 IF, Squelch, Mute and S meter circuit ■AF Amplifier ■Microphone Amplifier Circuit Fig. 5 Microphone amplifier circuit ■Modulation Circuit ■Drive and Final Circuit ■Transmission/Reception Switching Circuit ■Temperature Protection Circuit ■PLL Circuit ■VCO Circuit Fig. 8 PLL and VCO circuit ■Unlock Detection Circuit ■Charging Circuit ■Power Supply Switching Circuit ■Battery Type Recognition Circuit Fig. 10 Charging and Power supply switching circuit ■Reset and Backup Circuit ■Voltage Detection Circuit ■Battery Save Circuit ■LED Drive Circuit Fig. 13 LED drive circuit Fig. 12 Battery save circuit ■Key and Encoder Input Circuit 16 key (K, K2, M, M2 and E3 types) 4 key (E type) Fig. 14 Key and Encoder input circuit ■CTCSS/DCS ■DTMF ■VOX ■ Weather Alert (K and K2 types only) Fig. 15 CTCSS/DCS, DTMF, VOX, Weather alert ■Pin function TX-RXUNIT (X57-674X-XX) Page TH-K2AT/K2E/K2ET (Y50-580X-XX) TX-RXUNIT (X57-674X-XX) TH-K2AT/K2E/K2ET TX-RXUNIT (X54-674X-XX) 0-11 :K, K2 0-21 :M, M2 2-71 :E Page Page Page Page Page Page Page Page Page Operation B. Battery terminal reference voltage (7.5 V [Battery terminal]) D. S-meter(Two segments in S-meterlight, all segments in S-meterlight) E.RX BPF (Lower limit frequency, center frequency, upper limit frequency) Page Page Page L. DCS modulation balance O. VOX sensitivity (Level 1, level 9) Item Condition Adjustment Unit Terminal Note: If the Note: In the Page Note: Do not Page Page Page Terminal Unit Adjustment points TX-RXunit (A/3) Component side view TH-K2AT/K2E/K2ET PC BOARD TH-K2AT/K2E/K2ET Page PC BOARD TH-K2AT/K2E/K2ET 1 TH-K2AT/K2E/K2ET PC BOARD TH Page PC BOARD TH-K2AT/K2E/K2ET TH-K2AT/K2E/K2ET SCHEMATIC DIAGRAM Page Page Page Page TH-K2AT/K2E/K2ET SCHEMATIC DIAGRAM Transmitter Section Section Receiver Page Page Photo is K type