Kenwood TK-2302, TK-2302(V), TK-2306 Service Manual
VHF FM TRANSCEIVER
TK-2302/2302(V
TK-2306
SERVICE MANUAL
)
© 2008-9 PRINTED IN JA PAN
B51-8838-00 (N) 672
CONTENTS
Helical antenna
(T90-1036-15)
Badge (Front)
(B43-1622-04)
Button knob (PTT)
(K29-9425-03)
Button knob
(Side1/Side2)
(K29-9426-03)
Plastic cabinet assy
(A02-4040-03)
Knob (Selector)
(K29-9427-03)
Knob (Volume)
(K29-9309-13)
GENERAL .....................................................2
SYSTEM SET-UP .........................................3
REALIGNMENT ...........................................3
DISASSEMBLY FOR REPAIR ......................6
CIRCUIT DESCRIPTION ..............................9
SEMICONDUCTOR DATA .........................13
TERMINAL FUNCTION .............................13
COMPONENTS DESCRIPTION .................14
PARTS LIST ...............................................15
EXPLODED VIEW ......................................22
PACKING ....................................................23
ADJUSTMENT ..........................................25
PC BOARD
TX-RX UNIT (X57-7570-20) ...................30
SCHEMATIC DIAGRAM ............................34
BLOCK DIAGRAM .....................................38
LEVEL DIAGRAM ......................................40
SPECIFICATIONS ......................................41
This product complies with the RoHS directive for the European market.
.
This product uses Lead Free solder.
TK-2302/2302(V)/2306
Document Copyrights
Copyright 2008 by Kenwood Corporation. All rights re-
served.
No part of this manual may be reproduced, translated,
distributed, or transmitted in any form or by any means,
electronic, mechanical, photocopying, recording, or otherwise, for any purpose without the prior written permission
of Kenwood.
GENERAL
INTRODUCTION
SCOPE OF THIS MANUAL
This manual is intended for use by experienced tech ni cians familiar with similar types of commercial grade com mu ni ca tions equipment. It contains all required service
in for ma tion for the equipment and is current as of the publication date. Changes which may occur after publication
are covered by either Service Bulletins or Manual Revisions.
These are is sued as required.
Disclaimer
While every precaution has been taken in the preparation
of this manual, Kenwood assumes no responsibility for errors or omissions. Neither is any liability assumed for damages resulting from the use of the information contained
herein. Kenwood reserves the right to make changes to any
products herein at any time for improvement purposes.
PERSONAL SAFETY
The following precautions are recommended for personal
safety:
• DO NOT transmit until all RF connectors are verifi ed se -
cure and any open connectors are properly terminated.
• SHUT OFF and DO NOT operate this equipment near
elec tri cal blasting caps or in an explosive atmosphere.
• This equipment should be serviced by a qualifi ed tech ni -
cian only.
ORDERING REPLACEMENT PARTS
When ordering replacement parts or equipment in for ma tion, the full part identifi cation number should be in clud ed.
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 suffi cient description of the re quired component for proper identifi cation.
SERVICE
This transceiver is designed for easy servicing. Refer to
the sche mat ic diagrams, printed circuit board views, and
align ment procedures contained within.
Model Type TX-RX unit
TK-2302 K,P,M
TK-2302(V) K
TK-2306 M
X57-7570-20
Frequency
range
136~
174MHz
Remarks
IF1: 38.85MHz
LOC: 38.4MHz
2
SYSTEM SET-UP
TK-2302/2302(V)/2306
Merchandise received
Choose the type of transceiver
Transceiver programming
Are you using the optional antenna?
NO
Are you using the speaker microphone?
NO
Delivery
Frequency range (MHz) RF power Type
TX/RX 136~174
A personal computer, programming interface (KPG-22/22A),
and FPU (programming software) are required for programming.
(The frequency, TX power HI/LOW, and signalling data are
programmed for the transceiver.)
YES
YES
KRA-22 or KRA-26
Optional antenna
KMC-17, KMC-21 or KMC-45
Speaker microphone
5.0W
(Option)
TK-2302: K,P,M
TK-2302(V): K
TK-2306: M
1. Modes
User mode
PC mode
Wireless clone mode
Mode Function
User mode For normal use.
PC mode
Data programming
mode
PC test mode
Wireless clone
mode
Used for communication between the transceiver and PC.
Used to read and write frequency data and
other features to and from the transceiver.
Used to check the transceiver using the PC.
This feature is included in the FPU.
Used to transfer programming data from
one transceiver to another.
PC test mode
REALIGNMENT
Data programming mode
PC tuning mode
2. How to Enter Each Mode
Mode Operation
User mode Power ON
PC mode Received commands from PC
Wireless clone mode [PTT]+[Side2]+Power ON (Two seconds)
3. PC Mode
3-1. Preface
The transceiver is programmed by using a personal computer, a programming interface (KPG-22/22A, USB adapter
(KCT-53U)) and FPU (programming software).
The programming software can be used with a PC or
compatible. Figure 1 shows the setup of a PC for programming.
3-2. Connection Procedure
1. Connect the transceiver to the personal computer with
the interface cable and USB adapter (when the interface
cable is KPG-22A, the KCT-53U can be used).
3
TK-2302/2302(V)/2306
REALIGNMENT
Notes:
• You must install the KCT-53U driver in the computer to
use the USB adapter (KCT-53U).
• When using the USB adapter (KCT-53U) for the fi rst time,
plug the KCT-53U into a USB port on the computer with
the computer power ON.
2. When the POWER is switched on, user mode can be entered immediately. When the PC sends a command, the
transceiver enters PC mode.
When data is read from the transceiver, the red LED
lights.
When data is written to by the transceiver, the green LED
lights.
Notes :
• The data stored in the personal computer must match
Model Name and Model Type when it is written into EEPROM.
• Do not press the [PTT] key during data transmission or
reception.
3-3. KPG-22/KPG-22A Description
(PC programming interface cable : Option)
The KPG-22/22A is required to interface the transceiver
with the computer. It has a circuit in its D-sub connector
(KPG-22: 25-pin, KPG-22A: 9-pin) case that converts the RS232C logic level to the TTL level.
The KPG-22/22A connects the SP/MIC connector of the
transceiver to the RS-232C serial port of the computer.
3-4. KCT-53U Description (USB adapter : Option)
The KCT-53U is a cable which connects the KPG-22A to a
USB port on a computer.
When using the KCT-53U, install the supplied CD-ROM
(with driver software) in the computer. The KCT-53U driver
runs under Windows 2000 or XP.
3-5. FPU (Programming Software) Description
The FPU is the programming software for the transceiver
supplied on a CD-ROM. The software on this disk allows a
user to program the transceiver transceivers via Programming interface cable (KPG-22/22A).
PC
FPU
Tuning cable
(E30-3216-05)
PC
D-SUB
(25-pin)
KPG-22
Transceiver Transceiver Transceiver
D-SUB
(9-pin)
KPG-22 or KPG-22A or
KPG-22A+KCT-53U
Illustration is KPG-22
Gray
Gray/Black
1.5D-XV Lead wire
1.5D-XV Shield wire
PC
KPG-22A
+
–
+
–
PC
USB
KCT-53U
KPG-22A
Fig. 1
SP
MIC
3-6. Programming with PC
If data is transferred to the transceiver from a PC with the
FPU, the data for each set can be modifi ed.
Data can be programmed into the EEPROM in RS-232C
format via the SP/MIC jack.
In this mode the PTT line operate as TXD and RXD data
lines respectively.
List of FPU for transceiver
Model Type FPU
TK-2302 K,M KPG-118D(K)
TK-2302 P KPG-119D(K)
TK-2302(V) K KPG-119D(K)
TK-2306 M KPG-118D(M)
4
4. Wireless Clone Mode
4-1. Outline
“Wireless Clone Mode” copies the transceiver data to
another transceiver.
The dealer can copy the transceiver data to another trans-
ceiver even without the use of a personal computer.
4-2. Example
The transceiver can copy the programming data to one or
more transceivers via RF communication.
The clone source and clone target/s must be in wireless
clone mode.
REALIGNMENT
TK-2302/2302(V)/2306
4-3. Operation
1. To switch the clone target/s to wireless clone mode,
press and hold the [PTT] and [side2] keys while turning
the transceiver power ON.
2. Wait for 2 seconds. The LED will light orange and the
transceiver will announce “Clone”.
3. Select a channel table number using Side1 (increment
channel table) and Side2 (decrement channnel table)
keys.
4. To switch the clone source to wireless clone mode, press
and hold the [PTT] and [side2] keys while turning the
transceiver power ON.
5. Wait for 2 seconds. The LED will light orange and the
transceiver will announce “Clone”.
6. Select the same channel table number as the clone
target/s.
7. Press [PTT] on the clone source to begin data transmission.
When the clone target starts to receive data, the LED will
light green.
When the clone source fi nishes sending data, a “confi r-
mation” tone will sound.
If data transmission fails while cloning, an “error” tone
will sound from the target unit.
8. If the cloning fails, no data will be available in the target
unit when it is returned to User mode.
9. When the cloning is successful, the target unit’s “Scan”
and “Key lock” functions will return to their default values
(Scan = OFF, Key lock = OFF).
• Clone frequency table
No.
1 136.150
2 138.150
3 140.150
4 142.150
5 144.150
6 146.150
7 148.150
8 150150
9 152.150
10 154.150
11 156.150
12 158.150
13 160.150
14 162.150
15 164.150
16 166.150
17 168.150
18 170.150
19 172.150
20 174.150
Operating frequency
136~174MHz
Notes:
• The dealer can clone data to two or more transceivers by
repeating the above procedures.
• If the transceivers wireless clone mode is confi gured as
“Disabled”, the transceiver cannot enter wireless clone
mode.
• The table shown below will cover the frequency tables
used for wireless cloning.
• Wireless clone mode cannot be entered in battery low
state.
• A unit cannot be a “Source Unit” if it is unprogrammed. If
[PTT] is pressed, an “error” tone will sound.
• The language used in cloning depends on the “Model
type” setting, not the FPU setting.
• Once a unit is set to be the source, it cannot be a target
after the data has been transmitted. This protects the
data in the source unit.
• Electronic interface may cause a failure in data transfer
during wireless clone, such as when waveforms or electromagnetics are being performed at the workbench.
• Wireless clone mode can be used ONLY by the autho-
rized service personnel.
• The wireless clone mode setting must be confi gured
as “Disable” before being delivered to the end-user.
• To clone, replace the antenna from both the source
transceiver and the target transceiver with a dummy
load.
• The transmit output power is automatically set to
Low in wireless clone mode.
5
TK-2302/2302(V)/2306
DISASSEMBLY FOR REPAIR
1.
Removing the Case Assembly from the Chassis
1. Remove the volume knob q and channel knob w.
2. Remove the two screws e.
3. Lift and remove the chassis from the case assembly r.
(Use a fl at-blade screwdriver to easily lift the chassis.)
.
.
;
3. Removing the Battery Release Lever
from the Case Assembly
1. Press the upper part of the lever toward the inside of the
case assembly. One side of the shaft will be removed q.
@
:
2. Lift and remove the battery release lever from the case
assembly w.
@
:
4. Attaching the Battery Release Lever to
2.
Removing the TX-RX unit from the Chassis
1. Detach the solder of speaker wire from the PCB beforehand.
2. Remove the packing t from the SP/MIC jack of the TXRX unit.
3. Remove the ten screws y fi xing the TX-RX unit.
4. Remove the solder of the antenna terminal with a soldering iron u.
5. Remove the solder of the positive terminal with a soldering iron i.
Note: You can remove the TX-RX unit from the chas-
sis without removing the solder at the positive terminal.
However, in this case, you can not attach the packing
(G53-1605-03) that is on the positive terminal to the chassis in assembling. So, it is advisable to remove the solder
on the positive terminal fi rst.
6. Remove the FPC from the fl at cable connector o.
7. Lift and remove the TX-RX unit from the chassis !0.
>
the Case Assembly
1. Insert one side of the shaft into the hole at the lever fi tting section on the case assembly q.
Caution: The thin spring (G01-4543-04) should be posi-
tioned above the two tabs of the lever.
2. Tilt the battery release lever slightly forward w, so that
the thick spring (G01-4542-04) is positioned below the
case surface.
3. With the thick spring positioned below the case surface,
attach the other side of the shaft to the case assembly
by pressing the battery release lever e until it snaps into
place r.
Caution: Be careful not to tilt the battery release lever
too forward.
If the battery release lever is pushed in this state where
the two tabs come below the case surface, there is a
possibility of damaging the two tabs.
A thin spring
:
Shaft
@
Tow tabs
A thick spring
B
B
B
B
2
B
B
B
8
=
.
;
6
TK-2302/2302(V)/2306
DISASSEMBLY FOR REPAIR
5. Assembling the Battery Release Lever
1. Place the lever w onto the stopper q.
2. Place the thick spring e onto the lever.
3. Hook the right and left ends of the thin spring r onto the
tabs of the stopper, then place the thin spring onto the
lever t.
4. Slide the shaft through the hole of the stopper and lever
.
y
;
.
=
:
6.
Attaching the Positive Terminal to the Chassis
Always attach the positive terminal to the chassis, using
the following procedures, before mounting the TX-RX unit
onto the chassis.
1. Remove the holder assembly w from the packing q of
the positive terminal.
2. Mount the packing of the positive terminal into the chassis hole e.
3. Mount the holder assembly into the packing of the positive terminal r.
@
B
7.
Mounting the Chassis to the Case Assembly
1. Confirm that the waterproof packing attached to the
circumference of the chassis is securely inserted in the
groove of the chassis q.
2. Attach the speaker with waterproof packing to the
speaker recess of the case assembly w. Make sure the
speaker clasp is securely inserted.
3. Tighten the speaker clasp into the case assembly with
the screw.
4. Insert the upper part of the chassis into the case assembly e.
Caution: Take care that the speaker lead wire is not
caught by the microphone element.
5. Press the chassis r and the case assembly together to
attach them.
Caution: If the packing of the SP/MIC does not come
to the correct position after attaching the chassis to the
case assembly, reposition the packing with your fi ngers.
@
:
Confirm that the
waterproof packing is
securely inserted in the
groove of the chassis.
@
.
.
:
;
;
;
7
TK-2302/2302(V)/2306
DISASSEMBLY FOR REPAIR
8.
Attaching the Antenna Receptacle to the Chassis
Screw the antenna receptacle to the chassis in the order
shown in the drawing so that the antenna receptacle
comes to the center of the case hole.
10. Screw sequence for mounting the TX-
RX unit to the chassis
Attach the TX-RX unit to the chassis using the screws in
the order shown in the drawing below.
Note: From screw r onward no sequence is need.
;
Tighten this screw first.
Tighten this screw second
9.
The Nuts of the Volume Knob and Channel Knob
Note that the shapes, colors and heights of nuts of the
volume knob and channel knob are different from one
another. (The nut of volume knob is silver, and the nut of
channel knob is gold)
Use the following jig when removing the nuts of the vol-
ume knob and channel knob.
• Jig (Part No.: W05-1012-00)
Volume knob
(Long)
Channel knob
(Short)
;
;
TX-RX UNIT
Component side view
;
:
;;
;
.@
8
CIRCUIT DESCRIPTION
1. Frequency Confi guration
The receiver utilizes double conversion. The first IF is
38.85MHz and the second IF is 450kHz. The fi rst local oscillator signal is supplied from the PLL circuit.
The PLL circuit in the transmitter generates the neces-
sary frequencies. Fig. 1 shows the frequencies.
TX/RX : 136~174MHz
ANT
1st MIX
ANT
SW
TX
AMP
RF
AMP
RX:
174.85~
212.85MHz
TX: 136~174MHz
Fig. 1 Frequency confi guration
MCF
38.85MHz
RF
AMP
CF
450kHz
IF
SYSTEM
38.4MHz
X3
multiply
1/2
PLL
VCO
AF
AMP
TCXO
MIC
AMP
SP
12.8MHz
MIC
TK-2302/2302(V)/2306
First Mixer
■
The signal from the front end is mixed with the fi rst local
oscillator signal generated in the PLL circuit by Q203 to produce a fi rst IF frequency of 38.85MHz.
The resulting signal passes through the XF201 MCF to
cut the adjacent spurious and provide the opitimun characteristics, such as adjacent frequency selectivity.
IF Amplifi er Circuit
■
The fi rst IF signal is passed through a four-pole monolithic
crystal fi lter (XF201) to remove the adjacent channel signal.
The fi ltered fi rst IF signal is amplifi ed by the fi rst IF amplifier (Q202) and then applied to the lF system IC (IC201).
The IF system IC provides a second mixer, limiting amplifi er,
quadrature detector and RSSI (Received Signal Strength Indicator). The second mixer mixes the fi rst IF signal with the
38.4MHz of the second local oscillator output (TCXO X1 and
Q2) and produces the second IF signal of 450kHz.
The second IF signal is passed through the ceramic fi lter
(CF201) to remove the adjacent channel signal. The fi ltered
second IF signal is amplified by the limiting amplifier and
demodulated by the quadrature detector with the ceramic
discriminator (CD201). The demodulated signal is routed to
the audio circuit.
2. Receiver
The frequency confi guration of the receiver is shown in
Fig. 2.
ANT
ANT
SW
CF201
IC201
IF, MIX, DET
Q2
X3 multiplyX1TXCO
2nd Local 12.8MHz
Front End (RF AMP)
■
The signal coming from the antenna passes through the
transmit/receive switching diode circuit, (D103, D104 and
D105) passes through a BPF (L214, L216 and L213), and is
amplifi ed by the RF amplifi er (Q204).
The resulting signal passes through a BPF (L209 and
L211) and goes to the mixer. These BPFs are adjusted by
variable capacitors (D203, D204, D205 and D202). The input
voltage to the variable capacitor is regulated by voltage output from the MCU (IC306).
RF AMP
BPF
RCTV
Q204
AQUA-L
BPF
PCTV
AF VOL
IC308
Fig. 2 Receiver sectio
MIXER
Q203
1st Local
IC309
AF PA
MCF
XF201
IF AMP
Q202
SP
Wide/Narrow Switching Circuit
■
Narrow and Wide settings can be made for each channel
by switching the demodulation level.
The WIDE (low level) and NARROW (high level) data is
output from IC306, pin 5. When a WIDE (low level) data is
received, Q201 turn on. When a NARROW (high level) data
is received, Q201 turn off.
Q201 turns on/off with the Wide/Narrow data and the
IC201 detector output level is switched to maintain a constant output level during wide or narrow signals.
Q202
5R
W/N
(IC306)
L : Wide
H: Narrow
AFOUT
Q201
IC201
FM IF SYSTEM
QUAD IFOUT
R209
C209
R210
CD201
Fig. 3 Wide/Narrow switching circuit
Audio Amplifi er Circuit
■
The demodulated signal from IC201 goes to AF amplifi er
through IC308.
The signal then goes through an AF volume control , and
is routed to an audio power amplifi er (IC309) where it is amplifi ed and output to the speaker.
9
TK-2302/2302(V)/2306
CIRCUIT DESCRIPTION
Squelch
■
Part of the AF signal from the IC enters the FM IC (IC201)
again, and the noise component is amplifi ed and rectifi ed by
a fi lter and an amplifi er to produce a DC voltage corresponding to the noise level.
The DC signal from the FM IC goes to the analog port
of the MCU (IC306). IC306 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, IC306 sends a high
signal to the AF_CONT line and turns IC309 on through
Q312, Q313, Q314, Q315 and Q316. (See Fig. 4)
IC201: FM IF
IF amp
BUSY
QT/DQT IN
IC306
MCU
AF_CONT
Fig. 4 AF amplifi er and squelch
SIGNAL
DTMF
QT/DQT
CLK, DATA,
STD, LOADN
IC308
AQUA-L
IC309
AF PA
Q315,316
SW
Q312,313,314
SW
SP
3. PLL Frequency Synthesizer
The PLL circuit generates the fi rst local oscillator signal
for reception and the RF signal for transmission.
PLL
■
The frequency step of the PLL circuit is 2.5, 5, 6.25 or
7.5kHz.
A 12.8MHz reference oscillator signal is divided at IC1 by
a fi xed counter to produce an oscillator (VCO) output signal
which is buffer amplifi ed by Q3 then divided in IC1 by a programmable counter. The divided signal is compared in phase
with the 5, 10, 12.5 or 15kHz reference signal from the
phase comparator in IC1. The output signal from the phase
comparator is fi ltered through a low-pass fi lter and passed
to the VCO to control the oscillator frequency. (See Fig. 5)
VCO
■
The twice of operating frequency is generated by Q5 in
transmit mode and Q4 in receive mode. The oscillator frequency is controlled by applying the VCO control voltage,
obtained from the phase comparator, to the varactor diodes
(D4 and D8 in transmit mode and D3 and D6 in receive
mode).
The RX_SW pin is set high in receive mode causing Q7
turn on. The TX_SW pin is set high in transmit mode. The
outputs from Q4 and Q5 are amplifi ed by Q9 and sent to the
prescaler (IC2).
Receive Signaling
■
• QT/DQT
The output signal from FM IC (IC201) enters the MCU
(IC306) through IC308. IC306 determines whether the QT or
DQT matches the preset value, and controls the SP MUTE
and the speaker output sounds according to the squelch results.
• MSK (Fleet Sync)
The MSK input signal from the FM IC goes to pin 31 of IC
308. The signal is demodulated by MSK demodulator in IC
308. The demodulated data goes to the MCU for processing.
• DTMF
The DTMF input signal from the FM IC (IC201) goes to
IC308. The decoded information is then processed by the
MCU.
Unlock Detector
■
If a pulse signal appears at the LD pin of IC1, an unlock
condition occurs, and the DC voltage obtained from C4 and
Q1 causes the voltage applied to the MCU to go low. When
the MCU detects this condition, the transmitter is disabled,
ignoring the push-to-talk switch input signal.
Q3
LPF
PLL DATA
X1
12.8MHz
LPF
REF OSC
D4,8Q5TX VCO
D3,6Q4RX VCO
5,10,12.5 or 15kHz
1/N
comparator
1/M
5,10,12.5 or 15kHz
Q9
BUFF AMP
Q7,8
T/R SW
Phase
BUFFER
1/2
IC2
RX
TX
Charge
pump
IC1
PLL IC
10
Fig. 5 PLL circuit
TK-2302/2302(V)/2306
T
CIRCUIT DESCRIPTION
4. Transmitter System
Microphone Amplifi er
■
The signal from the microphone passes through the
IC308. When encoding DTMF, it is turned OFF for muting
the microphone input signal by IC308.
IC101 (2/2) compares the output voltage of IC101 (1/2)
with the reference voltage from IC306. The output of IC101
(2/2) controls the VG of the RF power amplifier and drive
amplifi er to make both voltages the same.
The change of power high/low is carried out by the
change of the reference voltage.
The signal passes through the Audio processor (IC308)
for the maximum deviation adjustment, and goes to the
VCO modulation input.
MIC
AGC
IC308
AQUA-L
VCO
Encode Signaling
■
• QT/DQT
QT/DQT data of the QTTCXO Line is output from pin 14
of the MCU. The signal passes through a low-pass CR fi lter
and goes to the TCXO (X1).
The QT/DQT data of the QTVCO Line is output from pin
15 of the MCU. The signal passes through a low pass CR fi l-
LPF
ter, mixes with the audio signal, and goes to the VCO modulation input. TX deviation is adjusted by the MCU.
IC306
MCU
DTMF
QTVCO
QTTCXO
LPF
X1
LPF TCXO
• DTMF
High-speed data is output from pin 74 of the MCU. The
signal passes through a low-pass CR fi lter, and provides a
TX and SP out tone, and is then applied to the audio proces-
Fig. 6 Microphone amplifi er
sor (IC308). The signal is mixed with the audio signal and
goes to the VCO.
TX deviation is adjusted by the MCU.
Drive and Final Amplifi er
■
The signal from the T/R switch (D10 is on) is amplifi ed
by the pre-drive (Q101) and the drive amplifier (Q102) to
800mW.
The output of the drive amplifi er is amplifi ed by the RF
• MSK (Fleet Sync)
Fleet Sync utilizes 1200bps and 2400bps MSK signal is
output from pin 6 of IC308. And is routed to the VCO. When
encoding MSK, the microphone input signal is muted.
power amplifier (Q105) to 5.0W (1W when the power is
low). The output of the RF power amplifi er is then passed
through the harmonic fi lter (LPF) and antenna switch (D103)
and applied to the antenna terminal.
From
/R SW
(D10)
+B
Q101 Q102
Pre-drive
AMP
VD
5T
R117
R120
R123
Drive
AMP
Q105
RF power
AMP
VG
VDD
D103
ANT
SW
VG
ANT
LPF
5. Power Supply
There are four 5V power supplies in the transceiver: 5M,
5C, 5R, and 5T. 5M for MCU is always output while the
power is on. 5M is always output, but turns off when the
power is turned off to prevent malfunction of the MCU.
5C is a common 5V and is output when SAVE is not set
to OFF.
5R is 5V for reception and output during reception.
5T is 5V for transmission and output during transmission.
6. Control Circuit
IC101
PCTV
(IC306)
(1/2)
Fig. 7 Drive and fi nal amplifi er and APC circuit
APC Circuit
■
The APC circuit always monitors the current flowing
through the drive amplifi er and RF power amplifi er (Q102
and Q105) and keeps a constant current.
The voltage drop at R117, R120 and R123 is caused by
the current flowing through the RF power amplifier and
drive amplifi er, and this voltage is applied to the differential
amplifi er IC101 (1/2).
IC101
(2/2)
The control circuit consists of a MCU (IC306) and its
peripheral circuits. It controls the TX-RX unit. IC306 mainly
performs the following:
1) Switching between transmission and reception by the
PTT signal input.
2) Reading system, group, frequency, and program data
from the memory circuit.
3) Sending frequency program data to the PLL.
4) Controlling squelch on/off by the DC voltage from the
squelch circuit.
5) Controlling the audio mute circuit by the decode data in-
put.
6) Transmitting tone and encode data.
11
TK-2302/2302(V)/2306
CIRCUIT DESCRIPTION
Frequency Shift Circuit
■
The MCU (IC306) operates at a clock of 14.746 MHz. This
oscillator has a circuit that shifts the frequency by BEAT
SHIFT SW (Q305, Q306).
A beat sound may be able to be evaded from generation
if “Beat Shift” is set to ON when it is generated in the internal spurious transmission modulated sound of a transceiver.
SB
R301
R305
66
IC306
MCU
Fig. 10 Low battery warning
IC306
MCU
XOUT XIN
X301
Hi: ON
Q305
Low: OFF
BSHIFT
Q306
Fig. 8 Frequency shift circuit
Memory Circuit
■
Memory circuit consists of the MCU (IC306) and an EEPROM (IC305). An EEPROM has a capacity of 16k bits that
contains the transceiver control program for the MCU and
data such as transceiver channels and operating features.
IC306 IC305
MCU
EEPROM
Fig. 9 Memory circuit
Low Battery Warning
■
The battery voltage is checked using by the MCU. The
transceiver generates a warning tone when it falls below
the warning voltage shown in the table.
1) The red LED blinks when the battery voltage falls below
the voltage (1) shown in the table during transmission.
Note: The transceiver checks the battery voltage during
reception even when, in the FPU, the Battery Warning
status function is set to “On TX” (default setting).
However, the LED does not blink during reception. Dur-
ing transmission, the LED blinks to generate the warning
tone of a low battery voltage.
2) The transceiver immediately stops transmission when
the battery voltage falls below the voltage (2) shown in
the table. A message tone beeps while the PTT switch is
released.
Ni-Cd Battery Ni-MH Battery Li-ion Battery
(1) 6.2V 6.2V 6.2V
(2) 5.9V 5.9V 5.9V
7. Control System
Keys and channel selector circuit. The signal from the
keys and channel selector are directly input to the MCU, as
shown in Fig. 11.
Channel
selector
55
PTT
62
61
60
59
58
EN1
EN2
EN3
EN4
EN5
IC306
MCU
SIDE1
SIDE2
56
57
Fig. 11 Control system
PTT
SW
SW1
SW2
12
SEMICONDUCTOR DATA
MCU: R5F212CCKCMB (TX-RX unit IC306)
Pin No. Signal Name I/O Function
1 5T_C O 5T control
2 PLL_STB O PLL strobe
3 5C_C O 5C control
4 5R_C O 5R control
5 W/N O Wide/Narrow switch
6 MODE I No function
7 AF_CONT O Speaker mute
8 BSHIFT O Beat shift control
9 RESET I MCU reset
10 XOUT O MCU clock (14.746MHz)
11 VSS - GND
12 XIN I MCU clock (14.746MHz)
13 VCC I Power supply input
14 QTTCXO O QT/DQT output
15 QTVCO O QT/DQT output
16~21 AUX6~AUX1 I/O No function
22 MIC_MUTE O MIC mute
23 AF_MUTE O No function
24~32 N.C O No function
33 RXDATA I No function
34 TXDATA O No function
35 OPTDET I Headset detect
36 TX_SW O TX VCO switch
37 RX_SW O RX VCO switch
38 LEDRX O Green LED control
39 LEDTX O Red LED control
40 APC_SW O APC switch
41 DC_SW O APC discharge switch
42 STD I Baseband IC data input
43 1/2 OSC O Baseband IC clock (3.6864MHz)
44 INT I No function
45 TXD O Serial data output
TK-2302/2302(V)/2306
Pin No. Signal Name I/O Function
46 RXD I Serial data input
47 DIR O Baseband IC data output
48 DI/O I/O Baseband IC data input / output
49 DTRLOADN O Baseband IC data output
50 TDATA/DTRCLK O Baseband IC data output
51 SCLK O Serial clock for baseband IC
52 TCLK/DTRDO I Baseband IC data input
53 RDF/FD I Baseband IC data input
54 MDSW I No function
55 PTT I PTT switch input
56 SIDE1 I Side1 key input
57 SIDE2 I Side2 key input
58~62 EN5~EN1 I Channel selector input
63 DIST1 I No function
64 DIST2 I No function
65 PLL_UL I PLL unlock signal input
66 BATT I Battery voltage detect
67 RSSI I RSSI input
68 BUSY I Busy signal input
69 VOX I VOX signal detect
70 QT/DQT_IN I QT/DQT signal input
71 EEPCLK O EEPROM clock
72 EEPDAT I/O EEPROM data input / output
73 TH_DET I Temperature detect
74 DTMF I DTMF/BEEP output
75 AVSS - GND
76 PCTV I APC/BPF control voltage
77 VREF I Reference voltage input
78 AVCC I Power supply input
79 PLL_DAT O PLL data output
80 PLL_CLK O PLL clock output
TERMINAL FUNCTION
TX-RX unit (X57-7570-20)
Pin No. Name I/O Function
CN301
1 B I B (Battery Voltage)
2 SB O Switched B
3 AFVOL_IN I Audio input
4 AFVOL_OUT O Audio output
5 AFVOL_GND - GND
Pin No. Name I/O Function
6 EN1 I Encoder pulse input
7 EN2 I Encoder pulse input
8 GND - GND
9 EN3 I Encoder pulse input
10 EN4 I Encoder pulse input
11 EN5 I Encoder pulse input
13
TK-2302/2302(V)/2306
COMPONENTS DESCRIPTION
TX-RX unit (X57-7570-20)
Ref. No. Part Name Description
IC1 IC PLL system IC
IC2 IC Prescaler
IC101 IC APC
IC201 IC FM system IC
IC301 IC Voltage detector/ Reset
IC303,304 IC Voltage regulator/ 5V
IC305 IC EEPROM
IC306 IC MCU
IC308 IC Audio processor
IC309 IC Audio amplifi er
Q1 Transistor Rectifi cation
Q2 Transistor Tripler
Q3 Transistor RF amplifi er
Q4 FET VCO/ RX
Q5 FET VCO/ TX
Q6 Transistor Rectifi cation
Q7 Transistor DC switch/ RX VCO
Q8 Transistor DC switch/ TX VCO
Q9 Transistor RF amplifi er
Q10 Transistor Ripple fi lter
Q11 Transistor RF amplifi er
Q101 Transistor RF amplifi er
Q102 FET TX drive amplifi er
Q103 Transistor Discharge switch
Q105 FET TX fi nal amplifi er
Q106 Transistor DC switch
Q107 FET DC switch
Q108 Transistor DC switch
Q201 Transistor Wide/Narrow switch/ RX
Q202 Transistor IF amplifi er
Q203 FET Mixer
Q204 FET Low noise amplifi er
Ref. No. Part Name Description
Q301 Transistor DC switch/ Red color LED
Q302 Transistor DC switch/ Green color LED
Q303 Transistor DC switch/ 5R
Q304 Transistor DC switch/ 5T
Q305,306 Transistor Beat shift switch
Q307 Transistor Wide/Narrow switch/ TX
Q308 Transistor Rectifi cation
Q310,311 Transistor MIC mute
Q312,313 Transistor DC switch
Q314 Transistor Mute switch
Q315,316 FET Mute switch
D3
D4
D6
D8
D9
D10 Diode TX/RX RF switch
D101 Zener diode Voltage protection
D103~105 Diode ANT switch
D202~205
D301 Diode Reverse voltage protection
D302 Diode Rectifi cation
D303 LED Red color LED
D304 LED Green color LED
D306 Diode Rectifi cation
D307 Diode Limiter
D308,309 Diode Rectifi cation
Variable Capcitance Diode
Variable Capcitance Diode
Variable Capcitance Diode
Variable Capcitance Diode
Variable Capcitance Diode
Variable Capcitance Diode
Frequency control/ RX VCO
Frequency control/ TX VCO
Frequency control/ RX VCO
Frequency control/ TX VCO
Modulator
RF BPF tuning
14
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