Kenwood TK-3107 Service Manual

UHF FM TRANSCEIVER

TK-3107

SERVICE MANUAL

M2 version

Antenna (T90-0694-15)

Knob (CHANNEL SELECTOR) (K29-5278-03)

Knob(VOLUME) (K29-5255-03)

CONTENTS

TK-3107 (16 channels)

Cabinet assy (A02-2448-13)

GENERAL.................................................................. 2

REALIGNMENT......................................................... 2

DISASSEMBLY FOR REPAIR................................... 4

CIRCUIT DESCRIPTION ........................................... 5

SEMICONDUCTOR DATA......................................... 8

DESCRIPTION OF COMPONENTS.......................... 9

PARTS LIST............................................................. 10

EXPLODED VIEW ................................................... 17

P ACKING................................................................. 18

ADJUSTMENT......................................................... 19

PC BOARD VIEWS

TX-RX UNIT (X57-6030-11) ................................ 23

SCHEMATIC DIAGRAM .......................................... 29

BLOCK DIAGRAM .................................................. 33

LEVEL DIAGRAM ................................................... 35

KNB-15A (Ni-Cd BATTERY) ................................... 36

SPECIFICATIONS ................................ BACK COVER

TK-3107

GENERAL/REALIGNMENT

INTRODUCTION

SCOPE OF THIS MANUAL

This manual is intended for use by experienced technicians familiar with similar types of commercial grade communications equipment. It contains all required service information for the equipment and is current as of the publication data. Changes which may occur after publication are covered by either Service Bulletins or Manual Revisions. These are issued as required.

ORDERING REPLACEMENT PARTS

When ordering replacement parts or equipment information, the full part identification number should be included. This applies to all parts : components, kits, or chassis. If the part number is not known, include the chassis or kit number of which it is a part, and a sufficient description of the required component for proper identification.

PERSONAL SAFETY

The following precautions are recommended for personal safety :

• DO NOT transmit until all RF connectors are verified secure

and any open connectors are properly terminated.

• SHUT OFF and DO NOT operate this equipment near

electrical blasting caps or in an explosive atmosphere.

• This equipment should be serviced by a qualified

technician only.

SERVICE

This radio is designed for easy servicing. Refer to the schematic diagrams, printed circuit board views, and alignment procedures contained within.

Destnation Number of CH RF power output

M2 16 4W

3 Getting acquainted

Microphone

SpeakerAntenna

Speaker/

microphone

jacks

① PTT (Push-To-Talk) switch

Press this switch, then speak into the microphone to call a station. Release the switch to receive.

② Monitor key

Press and hold to monitor how busy the current channel is and to monitor signals being received that do not contain the matched QT/DQT code.

③ Channel selector

Rotate to select channels 1 ~ 16.

➃ LED indicator

Lights red while transmitting, green while receiving a signal. Flashes red when the battery voltage is low while transmitting.

⑤ Power switch/ Volume control

Turn clockwise to switch the transceiver ON. Turn counterclockwise until a click sounds, to switch the transceiver OFF. Rotate to adjust the volume level.

REALIGNMENT

1 Modes

PC ModeUser Mode Manufacture Mode

MODE FUNCTION

User Mode Use this mode for normal operation. PC Mode Use this mode, to make various

settings by means of the FPU through the RS-232C port.

Manufacture Mode Use this mode, to realign the various

settings through the RS-232C port during manufacture work.

2 How to enter each mode

MODE PROCEDURE

User Mode Power ON PC Mode Connect to the IBM PC compatible

machine and controled by the FPU.

PC MODE

Preface

The transceiver is programmed by using a personal computer, programming interface (KPG-22) and programming software (KPG-55D).

The programming software can be used with an IBM PC or compatible. Figure 1 shows the setup of an IBM PC for programming.

Connenction procedure

1. Connect the TK-3107 to the personal computer with the

interface cable.

2. When data is transmitting from the transceiver the red LED

lights.

When data is received by the transceiver the green LED

lights.

Notes:

• The data stored in the personal computer must match the

Model Name when it is written into the EEPROM.

• Do not press the [PTT] key during data transmission or

reception.

REALIGNMENT

TK-3107

• KPG-22 description

(PC programming interface cable: Option) The KPG-22 is required to interface the TK-3107 with the computer. It has a circuit in its D-subconnector (25-pin) case that converts the RS-232C Iogic level to the TTL Ievel. The KPG-22 connects the side panel jacks of the TK-3107 to the computer's RS-232C serial port.

• Programming software description

The KPG-55D Programming Disk is supplied in 3-1/2" the disk format. The Software on this disk allows a user to program the TK-3107 radios via a Programming interface cable (KPG-22).

IBM-PC

KPG-55D

KPG-22

• Programming with IBM PC

If data is transferred to the transceiver from an IBM PC with the KPG-55D, the destination data (basic radio information) for each set can be modified. Normally, it is not necessary to modify the destination data because their values are determined automatically when the frequency range (frequency type) is set. The values should be modified only if necessary. Data can be programmed into the EEPROM in RS-232C format via the SP MIC plug. In this mode the PTT Iine operates as TXD and RXD data lines respectively.

Gray Gray/Black

1.5D-XV Lead wire Gray-XV Shield wire

}

MIC

RF Power meter or SSG

Tuning cable (E30-3216-05)

ANT

Fig. 1

TK-3107

DISASSEMBLY FOR REPAIR

Separating the case assembly from the chassis

1. Remove the two knobs ❶ and three round nuts ❷.

2. Remove the two screws ❸.

3. Expand the right and left sides of the bottom of the case assembly, Iift the chassis, and remove it from the case assembly ❹.

Separating the chassis from the unit

1. Remove the eleven screws ❻.

2. Remove the solder from the antenna terminal using a soldering iron then lift the unit off ❼.

3. Remove the two screws ❽ and remove the antenna connector.

Note : When reassembling the unit in the chassis, be sure to

solder the antenna terminal.

Antenna terminal

4. Taking care not to cut the speaker lead ➎, open the chassis and case assembly.

Removing the lever

1. Raise the lever on the lower case ➒, insert a small flat screwdriver into the space between the case and lever, open the case carefully ➓ and lift the lever off.

Note : Do not force to separate the case from the lever.

Lever knob

Cace assembly

CIRCUIT DESCRIPTION

TK-3107

1.Frequency configuration

The receiver utilizes double conversion. The first IF is

38.85MHz and the second IF is 450kHz. The first local oscillator signal is supplied from the PLL circuit. The PLL circuit in the transmitter generates the necessary frequencies. Fig. 1 shows the frequencies.

38.4MHz

450kHz

IF SYSTEM

multiply

PLL

VCO

AMP

TCXO

MIC

AMP

12.8MHz

MIC

ANT

ANT SW

AMP

MCF

38.85MHz

Fig. 1 Frequency configuration

2.Receiver

The receiver is double conversion superheterodyne, designed to operate in the frequency range of 470 to 490MHz. The frequency configuration is shown in Fig. 1.

1) Front - end RF amplifier

An incoming signal from the antenna is applied to an RF amplifier (Q203) after passing through a transmit/receive switch circuit (D102 and D103 are off) and a 3-pole LC filter. After the signal is amplified (Q203), the signal is filtered by a band pass filter (a 3-pole LC filter) to eliminate unwanted signals before it is passed to the first mixer.

The voltage of these diodes are controlled by to track the MPU (IC403) center frequency of the band pass filter. (See Fig. 2)

ANT

D102,D103

BPF

L208~L211

RF AMP

Q203

BPF

L214,L203,L204

MIXER

Q202

2) First Mixer

The signal from the RF amplifier is heterodyned with the first local oscillator signal from the PLL frequency synthesizer circuit at the first mixer (Q202) to create a 38.85MHz first intermediate frequency (1st IF) signal. The first IF signal is then fed through two monolithic crystal filters (MCFs : XF201) to further remove spurious signals.

3) IF amplifier

The first IF signal is amplified by Q201, and then enters IC200 (FM processing IC). The signal is heterodyned again with a second local oscillator signal within IC200 to create a 450kHz second IF signal. The second IF signal is then fed through a 450kHz ceramic filter (CF200) to further eliminate unwanted signals before it is amplified and FM detected in IC200.

XF201:L71-0522-05

Item Rating

Nominal center frequency 38.850MHz Pass band width ±5.0kHz or more at 3dB 40dB stop band width ±20.0kHz or less Ripple 1.0dB or less Insertion loss 4.0dB or less Guaranteed attenuation 80dB or more at fo -910kHz Terminal impedance 610 / 3PF

CF200:L72-0958-05

Item Rating

Nominal center frequency 450kHz 6dB band width ±6.0kHz or more 50dB band width ±12.5kHz or less Ripple 2.0dB or less at fo ±4kHz Insertion loss 6.0dB or less Guaranteed attenuation 35.0dB or more at fo ±100kHz Terminal impedance 2.0 k

ANT SW

TUNE

APC

IC403

MPU

CF200

MCF

XF201

IF AMP

Q201

TCXO

IF, MIX, DET

IC200

multiply

AF AMP

LPF, HPF

IC300

Fig. 2 Receiver section configuration

1st Local OSC

(PLL)

AF PA AMP

IC302

WIDE/NARROW SW

Q303

4) AF amplifier

The recovered AF signal obtained from IC200 is amplified by IC300 (1/4), filtered by the IC300 low-pass filter (2/4) and IC300 high-pass filter (3/4) and (4/4), and de-emphasized by R303 and C306. The AF signal is then passed through a WIDE/NARROW switch (Q303). The processed AF signal passes through an AF volume control and is amplified to a sufficient level to drive a loud speaker by an AF power

amplifier (IC302).

TK-3107

CIRCUIT DESCRIPTION

5) Squelch

Part of the AF signal from the IC enters the FM IC again, and the noise component is amplified and rectified by a filter and an amplifier to produce a DC voltage corresponding to the noise level. The DC signal from the FM IC goes to the analog port of the microprocessor (IC403). IC403 determines whether to output sounds from the speaker by checking whether the input voltage is higher or lower than the preset value. To output sounds from the speaker, IC403 sends a high signal to the MUTE and AFCO Iines and turns IC302 on through Q302, Q304, Q305, Q306 and Q307.(See Fig. 3)

IC200

FM IF IC

IF AMP DET

DET

MUTE

IC403

MPU

AFCO

BUSY

HPF AMP

56762

IC301

LPF

QT/DQT

IC300

AF AMP

Q303 W/N SW

6) Receive signaling

QT/DQT

300 Hz and higher audio frequencies of the output signal from IF IC are cut by a low-pass filter (IC301). The resulting signal enters the microprocessor (IC403). IC403 determines whether the QT or DQT matches the preset value, and controls the MUTE and AFCO and the speaker output sounds according to the squelch results.

LPF HPF

Q302

IC302

AF PA AMP

Q307

Q304, 305, 306 SW

Fig. 3 AF Amplifier and squelch

3.PLL frequency synthesizer

The PLL circuit generates the first local oscillator signal for reception and the RF signal for transmission.

1) PLL

The frequency step of the PLL circuit is 5 or 6.25kHz. A 12.8MHz reference oscillator signal is divided at IC1 by a fixed counter to produce the 5 or 6.25kHz reference frequency. The voltage controlled oscillator (VCO) output signal is buffer amplified by Q6, then divided in IC1 by a dual-module programmable counter . The divided signal is compared in phase with the 5 or 6.25kHz reference signal in the phase comparator in IC1. The output signal from the phase comparator is filtrered through a low-pass filter and passed to the VCO to control the oscillator frequency. (See Fig.4)

PLL IC IC1

5kHz/6.25kHz

I/N

PLL DATA

REF OSC

I/M

PHASE

COMPARATOR

5kHz/6.25kHz

CHARGE

PUMP

2) VCO

The operating frequency is generated by Q4 in transmit mode and Q3 in receive mode. The oscillator frequency is controlled by applying the VCO control voltage, obtained from the phase comparator, to the varactor diodes (D2 and D4 in transmit mode and D1 and D3 in receive mode). The T/R pin is set high in receive mode causing Q5 and Q7 to turn Q4 off, and turn Q3 on . The T/R pin is set low in transmit mode. The outputs from Q3 and Q4 are amplified by Q6 and sent to the buffer amplifiers.

D2, 4

LPF

D1, 3

TX VCO

RX VCO

BUFF AMP

Q5, 7

T/R SW

RF AMP

12.8MHz

Fig. 4 PLL circuit

CIRCUIT DESCRIPTION

TK-3107

3) UNLOCK DETECTOR

If a pulse signal appears at the LD pin of IC1, an unlock condition occurs, and the DC voltage obtained from D7, R6, and C1 causes the voltage applied to the UL pin of the microprocessor to go low. When the microprocessor detects this condition, the transmitter is disabled, ignoring the push-totalk switch input signal. ( See Fig.5)

IC1

PLL IC

IC403

MPU

Fig. 5 Unlock detector circuit

4. Transmitter

1) Transmit audio

The modulation signal from the microphone is amplified by IC500 (1/2), passes through a preemphasis circuit, and amplified by the other IC500 (1/2) to perform IDC operation. The signal then passes through a low-pass filter (splatter fiIter) (Q501 and Q502) and cuts 3kHz and higher frequencies. The resulting signal goes to the VCO through the VCO modulation terminal for direct FM modulation. (See Fig. 6)

2) QT/DQT encoder

A necessary signal for QT/DQT encoding is generated by IC403 and FM-modulated to the PLL reference signal. Since the reference OSC does not modulate the loop characteristic frequency or higher, modulation is performed at the VCO side by adjusting the balance. (See Fig. 6)

Q501, 502

LPF

(SPLATTER FILTER)

IC403

MIC

IC500 (1/2)

MIC

AMP

Q503 SW

PREEMPHASIS

IC500 (1/2)

IDC

MUTE

Fig. 6 Transmit audio QT/DQT

3) VCO and RF amplifier

The transmit signal obtained from the VCO buffer amplifier Q100, is amplified by Q101 and Q102. This amplified signal is passed to the power amplifier, Q105 and Q107, which consists of a 2-stage FET amplifier and is capable of producing up to 4W of RF power. (See Fig.7)

4) ANT switch and LPF

The RF amplifier output signal is passed through a lowpass filter network and a transmit/receive switching circuit before it is passed to the antenna terminal. The transmit/ receive switching circuit is comprised of D101, D102 and D103. D102 and D103 are turned on (conductive) in transmit mode and off (isolated) in receive mode.

VR501

MAX DEV

QT/DQT

VR500

BALANCE

X1, IC1

REFERENCE

OSC

(TCXO)

D5, Q4

VCO

DRIVE AMP

Q105

APC

IC100

Q108 SW

Q109

FINAL AMP

Q107

Q106

ANT SW

D101

LPF

ANT SW

D102,103

APC

AMP

Q101,Q102

Q103, Q104 B SW

TH102

DET

Q110

Fig. 7 APC system

5) APC

The automatic power control (APC) circuit stabilizes the transmitter output power at a predetermined level by sensing the drain current of the final amplifier Field Effect Transistor (FET) . The voltage comparator, IC100 (2/2), compares the voltage obtained from the above drain current with a reference voltage which is set using the microprocessor. An APC voltage proportional to the difference between the sensed voltage and the reference voltage appears at the output of IC100 (1/2). This output voltage controls the gate of the FET power amplifier, which keeps the transmitter output power constant. The transmitter output power can be varied by the microprocessor which in turn changes the reference voltage and hence, the output power.

6) Terminal protection circuit

When the thermistor (TH102) reaches about 80˚C, the protection circuit turns on Q110 to protect transmitting final amplifier (Q107) from the over heating.

5. Power supply

A 5V reference power supply [5M] for the control circuit is derived from an internal battery. This reference is used to provide a 5V supply in transmit mode [5T], a 5V supply in receive mode [5R], and a 5V supply common in both modes [5C] based on the control signal sent from the microprocessor.

6. Control system

The IC403 CPU operates at 7.37MHz . This oscillator has a circuit that shifts the frequency according to the EEPROM data.

ANT

TK-3107

Microprocessor: M38267M8L241GP (IC403)

Pin No.

I/O Port Name Function

1 O VC1 NC 2 O VC2 NC 3 I NC NC

4 I TIBI 5 I TI QT/DQT signal input

6 I BUSY Busy input 7 l BATT Battery voltage detection 8 l NC NC

9 O VCCN Frequency regulation output 10 O APC/TUNE 11 I NC NC

12 I NC NC 13 l NC NC 14 l NC NC 15 O BEEP Beep output 16 O TO QT/DQT output 17 l NC NC 18 I PTT [PTT] key input Connected to RXD

19 O TXD 20 I RXD

21 l NC NC 22 I SELF Self program L : disable 23 I MONl [MONl] key input 24 I NC NC 25 I NC NC 26 I NC NC 27 l NC NC 28 l ENC3 Encode input (channel select) 29 l ENC2 Encode input (channel select) 30 l ENC1 Encode input (channel select) 31 l ENC0 Encode input (channel select) 32 l INTO Power detection control 33 I RST Reset input 34 I NC NC 35 O NC NC 36 l XIN 7.3728MHz oscillator 37 O XOUT 7.3728MHz oscillator 38 I VSS GND 39 O SHIFT Beat shift H : shift on 40 O PABC Final supply H : on

41 O WNRC 42 O WNTC MAX Dev. Control Narrow: H

43 l NC NC 44 l NC NC 45 I NC NC 46 l NC NC 47 l/O SDA EEPROM data line 48 O SCL EEPROM clock line 49 I UL PLL unlock detection pin L : unlock 50 l NC NC 51 I NC NC 52 I NC NC 53 l NC NC 54 I NC NC 55 O DT Common data output 56 O CK Common clock output 57 O NC NC 58 O LE PLL IC enable H : Iatches

QT/DQT external circuit center point input

TX : Auto power control D/A output RX : BPF tuning D/A output

RS-232C output Connected to SP/ MIC test(REM)

RS-232C input Connected to [PTT] line

Audio reference sensitivity L : narrow

SEMICONDUCTOR DATA

Pin No.

100 I NC NC

FET : 2SK2596(Q105)

Item V

Rating 17V ±10V 0.4A 3W 150°C -45~+150°C

FET : 2SK2595(Q107)

Item V

Rating 17V ±10V 1.1A 20W 150°C -45~+150°C

I/O Port Name Function

59 O NC NC 60 O NC NC

61 O 5MC

62 O AFCO AF amp power suppIy H : ON 63 O RX TX/RX VCO select H : RX 64 O GLED Green LED control H : Lit 65 O RLED RED LED control H : Lit 66 O SAVE Save control

67 O MUTE 68 O 5RC 69 O 5TC

70 O NC NC 71 O NC NC 72 O NC NC 73 O NC NC 74 O NC NC 75 O NC NC 76 O NC NC 77 O NC NC 78 O NC NC 79 O NC NC 80 O NC NC 81 O NC NC 82 O NC NC 83 O NC NC 84 O NC NC 85 O NC NC 86 O NC NC 87 O NC NC 88 O NC NC 89 l VCC Microcomputer power supply, 5V input

90 l VREF 91 l AVSS

92 O NC NC 93 O NC NC 94 O NC NC 95 O NC NC 96 I NC NC 97 l NC NC 98 I NC NC 99 I NC NC

Absolute Maximum Ratings (Ta=25°C)

DSS

GSS

Absolute Maximum Ratings (Ta=25°C)

GSS

Control of power supply (5M) for everything except the

microcomputer and EEPROM L : Power supply ON

H : Save off

Mute control H : Mic mute L : AF mute

Reception power suppIy control Transmission power suppIy control

A/D conversion reference voltage ; connected to Vcc

A/D converter power supply ; connected to Vss

Pch* Tch Tstg

*Tc=25°C

Pch* Tch Tstg

*Tc=25°C

L : on H : on

DESCRIPTION OF COMPONENTS

TK-3107

Ref No.

IC1 IC

IC100 IC AUTOMATIC POWER CONTROL IC200 IC IF SYSTEM IC300 IC AUDIO AMP ACTIVE FILTER IC301 IC ACTIVE FILTER IC302 IC AUDIO POWER AMP IC400 IC RESET SWITCH IC401 IC EEPROM IC402 IC VOLTAGE DETECT IC403 IC MICRO PROCESSOR IC404 IC VOLTAG E REGULATER IC500 IC MIC AMP/LIMITER

Q1 TRANSISTOR TRIPLER Q2 TRANSISTOR RF AMP Q3 FET VCO RX Q4 TRANSIST OR VCO TX Q5 FET DC SWITCH Q6 TRANSISTOR RF BUFFER AMP Q7 TRANSISTOR DC SWITCH

Q8 TRANSISTOR RIPPLE FILTER Q100 TRANSISTOR RF AMP Q101 TRANSISTOR TX PRE-DRIVE Q102 FET TX DRIVE Q103 FET DC SWITCH Q104 TRANSISTOR DC SWITCH Q105 FET TX DRIVE Q106 FET DC SWITCH Q107 FET TX FAINAL

Q108,109

Q110 TRANSISTOR Q200 TRANSISTOR DC SWITCH

Q201 TRANSISTOR IF AMP Q202 FET MIXER Q203 FET MIXER RF AMP Q300 TRANSISTOR ACTIVE FILTER Q302 FET AUDIO MUTE SWITCH

Q303-306

Q307 FET AUDIO MUTE SWITCH

Q400-402

Q403 TRANSISTOR BEAT SHIFT SWITCH Q404 TRANSISTOR DC SWITCH Q405 FET DC SWITCH

Q406-408

Q500 FET DC SWITCH

Q501,502

Q503 TRANSISTOR MIC MUTE/ AGC Q504 TRANSISTOR DC SWITCH

D1-4

D6 DIODE CURRENT STEERING

D7 DIODE UNLOCKDETECT D100 DIODE RF SWITCH

D101-103

D200 DIODE RF SWITCH

D201-205

D300 DIODE LIMITER D400 LED TX D401 LED BUSY D500 DIODE AGC DETECT D501 DIODE MIC MUTE/AGC SWITCH D502 DIODE REVERSE PROTECTION

Semiconductor Description

PHASE LOCKED LOOP SYSTEM

TRANSISTOR DC SWITCH

TRANSISTOR ACTIVE FILTER

VARIABLE CAPACITANCE DIODE VARIABLE CAPACITANCE DIODE

DIODE ANTENNA SWITCH

VARIABLE CAPACITANCE DIODE

TEMPERATURE PROTECTION SWITCH

FREQ. CONTROL

TX MODULATION

BPF TUNING

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