TTI TCB660 Service Manual
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SERVICE
MANUAL
MULTI CHANNEL AM/FM TRANSCEIVER
TCB-660
TTI Tech Co.,Ltd.
TABLE OF CONTENTS
SECTION 1 SPECIFICATIONS
SECTION 2 CIRCUIT DESCRIPTION
1 GENERAL
2 TECHNICAL DESCRIPTION
3 SEMICONDUCTORS AND FUNCTION
4 DESCRIPTION OF FREQUENCY DETERMINING AND STABILIZING CIRCUIT
5 TEST EQUIPMENT SETUP AND ALIGNMENT INSTRUCTIONS
SECTION
SECTION
SECTION 5 BOARD LAYOUT
SECTION 6 BLOCK DIAGRAM
SECTION 7 SCHEMATIC
3 PART LIST
4 MECHANICAL DISASSEMBLY
5-1 MAIN PCB
5-2 FRONT PCB
5-3 VOLUME PCB
SECTION1 SPECIFICATIONS
Channel
Frequency Range
Operating mode
G
Frequency Control
E
Frequency Tolerance
N
E
Operating Temperature Range
R
Microphone
A
Input Voltage
L
Size
Weight
Antenna Connector
T
Power Output
R
Modulation
A
N
S
M
Frequency Response
I
Output Impedance
T
T
Harmonic Suppression
E
Current Drain
R
40 (See the frequency band chart)
26.96 MHz ~ 27.99125 MHz
F3E (FM), A3E (AM)
PLL Synthersizer
0.002%
-10 to + 55 C
Plug-in Type
13.2V DC ± 15%
140 (W) x 186 (L) x 37 (H)
990 g
Antenna Connector
Duty cycle 10% 4 Watts @13.2V DC
AM:from 85% to 95%
FM:1.8KHz ± 0.2KHz
300Hz to 3000Hz
50ohms, Unbalanced
More than -36dBm
AM Full Mod. 1.6A Max.
Receiving System
IF Frequencies
Sensitivity
R
Dual conversion superheterodyne
Double Conversion 1st 10.695MHz/2nd 455KHz
0.7 V for 10dB(S+N)/N
in AM Mode
0.5 V for 20dB SINAD in FM Mode
E
Audio Output Power
C
Audio Distortion
E
I
Image Rejection
V
Adjacent Channel Rejection
2.0W @ 8 Ohm
Less then 8% @ 1KHz
60 dB
60 dB
E
Conducted Spurious
R
Frequency Response
Built-in Speaker
Squelch
More than 60 dB
300 to 2500Hz
8 Ohms, round
Adjustable; Threshold less than 1 microvolt
* Specification is subject to change without prior notice.
SECTION2 CIRCUIT DESCRIPTION
------------ Contents -------------
1 General
1-1. Receiver
1.2. Transmitter
2. Technical Description
2-1. General
2-2. Type of emission
2-3. Frequency Table
2-4. RF Power Output
2-5. DC input Voltage and Current with 13.2V DC Input to Power AMP
2-6. Receiver IF and Local Oscillator Frequencies
3. Semiconductors and Function
4. Description of Frequency Determining and Stabilizing Circuit
4-1. Introduction
4-2. Basic Synthesis Scheme
4-3. Descriptions of Each Block
4-3-1. Introduction
4-3-2. Reference Frequency
4-3-3. VCO
4-3-4. Programmable Divider and Its Control
4-3-5 Phase Detector and VCO Control
4-3-6. Transmitter / Receiver Buffer AMP
4-3-7. Transmitter Doublers
4-3-8. Switching of Turning Capacitor in VCO
4-3-9. Receiver Local Oscillator Outputs
4-4. Frequency Stability
4-5. Description of other Circuits
4-5-1. Transmitter
4-5-2. Receiver
5. Test Equipment Setup and Alignment Instructions
5-1. General Section
5-2. Transmitter Section
5-3. Receiver Section
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TCB-660 Circuit Description Page 2
1. General
1-1. Receiver
① Display : 40 Channels and other functions indication
② Frequency Range : 26.965 to 27.405 [MHz]
③ Frequency Response : 300 to 2,500 [Hz]
④ Power Source : 13.2 [V] DC
⑤ Audio Output Load : 8 [OHM]
⑥ Audio Output : 4.0 [W] (or More)
⑦ Squelch : Adjustable from 0.2[uV] to 100 [uV]
⑧ Sensitivity :
- FM : 20 dB [SINAD] under 1.0 [uV] RF Signal or less
- AM :10 dB [S/N] under 1.0 [uV] RF Signal or less
⑨ Intermediate Frequency :
- 1st IF : 10.695 [MHz]
- 2nd IF : 455 [KHz]
1-2. Transmitter
① Carrier Power(Conducted)
② Current Drain ( 13.2 [V] Supply Voltage)
- No Modulation : 1,
- Max Modulation : 1
③ Modulation Capabilities
- AM : ± 90 [%]
- FM : ± 1.8 [KHz/Dev]
④ Spurious Radiation : Less then 74 [dBc]
⑤ Antenna Impedance : 50 [OHM]
⑥ Frequency Tolerance : 0.002 [%]
: AM 4 [W] / FM 4 [W]
100 [mA]
,600 [mA]
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TCB-660 Circuit Description Page 3
2. Technical Description
2-1. General
2-2. Type of emission : AM(A3E) , FM(F3E)
Model TCB-660 is an mobile type AM/FM radio transceiver for use of the Citizen Radio Service.
z Front Panel Controls
① LCD (C
② Receiver Audio Control (With Power ON/OFF Control) Volume
③ Squelch Control Volume
④ Channel UP/Down Key Switch
⑤
AM/FM Select Key
⑥
Scan Key
z Accessorily Connectors
① Antenna Socket
② External Speaker Jack
③ Microphone(Condenser Microphone)
hannel and RX/TX
).
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TCB-660 Circuit Description Page 4
2-3. Frequency Table
Channel Frequency (MHz) Channel Frequency (MHz)
1 26.965 21 27.215
2 26.975 22 27.225
3 26.985 23 27.235
4 27.005 24 27.245
5 27.015 25 27.255
6 27.025 26 27.265
7 27.035 27 27.275
8 27.055 28 27.285
9 27.065 29 27.295
10 27.075 30 27.305
11 27.085 31 27.315
12 27.105 32 27.325
13 27.115 33 27.335
14 27.125 34 27.345
15 27.135 35 27.355
16 27.155 36 27.365
17 27.165 37 27.375
18 27.175 38 27.385
19 27.185 39 27.395
20 27.205 40 27.405
2-4. RF Power Output
z AM : 4.0 [W]
z FM : 4.0 [W]
2-5. DC Iinput Voltage and Current with 13.2V DC Input to Power AMP
z Transmitter Power Amp : Voltage 12.5 V
z Transmitter Driver Amp : Voltage 12.5 V
2-6. Receiver IF and Local Oscillator Frequencies
z First IF : 10.695 [MHz]
z Second IF : 455 [KHz]
z First Local Oscillator : 10.695 [MHz] Below Receiving Frequency
z Second Local Oscillation : 10.240 [MHz]
Current 820 mA
Current 130 mA
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TCB-660 Circuit Description Page 5
3. Semiconductors and Function
3-1. Transistor
--------------------------------------------------------------------------------------------------------------------------------------------
Ref No. Description Manufacturer Function
--------------------------------------------------------------------------------------------------------------------------------------------
Q101 KTC3880S KEC RX Amplifier
Q102 KTK211 KEC 1’st Mixer
Q103 KTK211 KEC 1’st Mixer
Q104 KRC101S KEC RX Band1 Switching
Q105 KRC101S KEC RX Band2 Switching
Q151 KTC3875S KEC RX FM AF Amplifier
Q152 KRC112S KEC FM AF Mute at AM Mode
Q153 KRC101S KEC FM AF Mute at AM Mode
Q154 KRC112S KEC RX AF Mute at TX Mode
Q161 KTC3880S KEC AM IF Amplifier
Q162 KTC3880S KEC AM IF Amplifier
Q163 KRA102S KEC RX AM B+
Q164 KTA1504S KEC Automatic Noise Level Control
Q181 KTC3875S KEC RX RF Mute at TX Mode
Q182 KTC3875S KEC AGC
Q183 KTC3875S KEC AGC
Q201 KRC101S KEC AF Mute
Q202 KRC202S KEC AF Path
Q233 KTA1504S KEC Automatic Level Control
Q234 KTC3875S KEC Automatic Level Control
Q301 KTC3880S KEC VCO
Q302 KTC3880S KEC RX/TX VCO Buffer
Q303 KTC3880S KEC VCO Buffer
Q305 KRC101S KEC TX VCO Control
Q311 KRC101S KEC RX Band1 Switching
Q312 KRC101S KEC RX Band2 Switching
Q313 KRC101S KEC RX Band3 Switching
Q502 KTC3875S KEC FM TX AF Mute at AM TX
Q701 KTC3880S KEC TX Doublers
Q702 KTC3880S KEC TX Pre-Amplifier
Q703 KTC1006 KEC TX Driver Amplifier
Q704 2SC2078 SANYO TX Power Amplifier
Q742 KTC3875S KEC TX RF Mute at RX Mode
Q801 KRC101S KEC CPU Reset
Q802 KRC101S KEC CPU RX/TX Control
Q803 KRA101S KEC MIC Lock Control
Q911 KTA1658 KEC Main Regulator
Q912 KRA1504S KEC Main Regulator
Q913 KRC112S KEC Main Regulator Control
Q914 KRC102S KEC Power Low Control
Q921 KTC3875S KEC 8.2V Regulator
Q923 KTC3875S KEC RX B+
Q924 KRA1504S KEC TX B+
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TCB-660 Circuit Description Page 6
Q951 KTA1241 KEC Back Light LED Control
Q952 KTA1241 KEC Back Light LED Control
Q953 KRC101S KEC Back Light LED Control
Q954 KRC101S KEC Back Light LED Control
Q961 KRC110S KEC TX AF Mute at RX Mode
Q962 KRC111S KEC MIC AF Path at AM Mode
3-2. IC
--------------------------------------------------------------------------------------------------------------------------------------------
Ref No. Description Manufacturer Function
--------------------------------------------------------------------------------------------------------------------------------------------
IC101 TK144889V TOKO IF IC
IC102 KIA358F KEC AGC, Squelch Control
IC201 TDA2003 ST AF Power Amplifier
IC301 LC7152NM SANYO PLL
IC401 KIA4558F KEC FM TX AF
IC801 JT5BL9 TOSHIBA CPU
IC802 24WC02 ATMEL EEPROM
3-3. Manufacture Information
z KEC ---------------------- KEC Co., LTD.
z SANYO ---------------------- SANYO Semiconductor Co., LTD.
z TOKO ---------------------- TOKO, Inc.
z TOSHIBA ---------------------- Toshiba Semiconductor. Co., LTD.
z ATMEL ---------------------- ATMEL Co., LTD
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TCB-660 Circuit Description Page 7
4. Description of Frequency Determining and Stabilizing Circuit
4-1. Introduction
The Frequencies for transmitter and receiver first local frequencies are all derived from a signal
4.5MHz crystal by means of a phase locked loop(PLL).
The first local oscillator frequencies are 16.270MHz(CH1) to 16.710MHz(CH40). The second local
frequency is fixed at 10.240MHz to generate second IF 455KHz.
Transmit, the VCO of the PLL operates 13.4825MHz(CH1) to 13.7025MHz(40CH). The VCO frequency
goes to the doublers circuit Q701, L701, L702 with doubles the frequency to generate 26.965MHz(CH1)
to 27.405MHz(40CH).
Q302
VCO
13.4825MHz(CH1)
~
13.7025MHz(CH40)
The VCO operating frequency for the receiver is 16.27MHz(CH1) to 16.710MHz(CH40) as the
first local oscillator, injected through the buffer amplifier Q302 into the first FET balanced mixer Q102,
Q103.
4-2. Basic Synthesis Scheme
The crystal frequency(4.5MHz) is divided by 1800 times to make 2.5KHz which is fed to one
side of the phase detector. The VCO output is divided by a programmable divider, and fed to other side of
the phase detector Pin 9, 10 of IC301. Passing the phase detector output closes the feedback loop through
an active low pass filter and using the output to control the VCO frequency through varicap diode D301.
Under locked conditions, both of phase detector input signal must be identical at 2.5KHz.
The VCO frequency is then given by ;
Receiver : Fvco / N = 0.005 [MHz] OR Fvco = 0.005 X N [MHz]
Transmitter : Fvco / N = 0.0025 [MHz] OR Fvco = 0.0025 X N [MHz]
Since “N” is an integer, the VCO frequency can be stepped up with in receiver mode 5KHz and
transmitter mode 2.5KHz increments.
By suitable choice of “N” the desired output frequency can be obtained.
27.405MHz(CH40)
Q701
Doublers
26.965MHz(CH1)
To transmitter
~
Channel 1 Channel 40
N Fvco N Fvco
Transmit 5393 13.4825 5481 13.7025
Receiver 3254 16.2700 3342 16.7100
See the [Table 1]for other Channels
The VCO frequency goes to the doublers circuit, with doubles the incoming signals.
VCO Output Frequency Doublers Output Frequency
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TCB-660 Circuit Description Page 8
Transmit
---
---
---
Transmit
Since all frequencies are obtained from the crystal controlled PLL oscillator, all outputs are
coherent with the crystal oscillator frequency and matching the sample percentage accuracy.
Note that the reference frequency of 5KHz(receiver) and 2.5KHz(transmitter) is obtained by
dividing the 4.5MHz by 900 times and 1800 times
See Table 1 for transmitter/receiver mode VCO frequencies.
CH 1 , 13.4825 MHz
CH 40 , 13.7025 MHz
26.965 MHz
27.405 MHz
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TCB-660 Circuit Description Page 9
Program Data & Frequency[Table 1]
Channel
1 26.965 3254 16.27
2 26.975 3256 16.28
3 26.985 3258 16.29
4 27.005 3262 16.31
5 27.015 3264 16.32
6 27.025 3266 16.33
7 27.035 3268 16.34
8 27.055 3272 16.36
9 27.065 3274 16.37
10 27.075 3276 16.38
11 27.085 3278 16.39
12 27.105 3282 16.41
13 27.115 3284 16.42
14 27.125 3286 16.43
15 27.135 3288 16.44
16 27.155 3292 16.46
17 27.165 3294 16.47
18 27.175 3296 16.48
19 27.185 3298 16.49
20 27.205 3302 16.51
21 27.215 3304 16.52
22 27.225 3306 16.53
23 27.255 3312 16.56
24 27.235 3308 16.54
25 27.245 3310 16.55
26 27.265 3314 16.57
27 27.275 3316 16.58
28 27.285 3318 16.59
29 27.295 3320 16.60
30 27.305 3322 16.61
31 27.315 3324 16.62
32 27.325 3326 16.63
33 27.335 3328 16.64
34 27.345 3330 16.65
35 27.355 3332 16.66
36 27.365 3334 16.67
37 27.375 3336 16.68
38 27.385 3338 16.69
39 27.395 3340 16.70
40 27.405 3342 16.71
Frequency
[MHz]
N Fvco N Fvco
RX TX
5393
5395
5397
5401
5403
5405
5407
5411
5413
5415
5417
5421
5423
5425
5427
5431
5433
5435
5437
5441
5443
5445
5451
5447
5449
5453
5455
5457
5459
5461
5463
5465
5467
5469
5471
5473
5475
5477
5479
5481
13.4825
13.4875
13.4925
13.5025
13.5075
13.5125
13.5175
13.5275
13.5325
13.5375
13.5425
13.5525
13.5575
13.5625
13.5675
13.5775
13.5825
13.5875
13.5925
13.6025
13.6075
13.6125
13.6275
13.6175
13.6225
13.6325
13.6375
13.6425
13.6475
13.6525
13.6575
13.6625
13.6675
13.6725
13.6775
13.6825
13.6875
13.6925
13.6975
13.7025
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TCB-660 Circuit Description Page 10
4-3. Descriptions of Each Block
4-3-1. Introduction
The synthesizer is implemented with the following components;
PLL IC (IC301)
X-TAL (X301)
VCO, VARICAP DIODE (D301)
IC1301 is CMOS LSI that includes most of PLL block.
The Q301, L301, C311, C312, C313, C314, varicap diode D301 are clap oscillator circuit to
operate as a VCO of the IC301. Q305 is a switching transistor to connect or disconnect the tuning
capacitor in the VCO oscillator tank circuit for transmitter or receiver.
Q302 works as a buffer amplifier for RX local frequencies (≒16MHz) and TX carrier
generating frequencies(≒13MHz)
4-3-2. Reference Frequency
The cry stal X301(4.5MHz) and other components at Pin 1 and 24 of IC301 can make a reference
frequency oscillator with internal amplifier.
4-3-3. VCO
Q301 and surrounding parts are consisting a clap oscillator works as a VCO of IC301. With
appropriate control voltage on D301 the VCO can be oscillate over the required range of 13.4825MHz to
16.710MHz.
4-3-4. Programma
The programmable input for each channel are stetted by the PLL Clock(Pin 11), PLL Data(Pin
12), PLL Enable(Pin 13) of IC801. Each input signal to control the PLL ic is done with provide key input
Pin 18, 19, 25, 26, 27, 28, 29, 32, 33, 34, 35, 37. For each key input, an internal code converts EEPROM
appropriate control to the programmable divider for that channel.
Since the change transmit and receive, and additional bit is required at Pin 8 of IC801 to allow
the ROM to recognize the status TX or RX.
During transmit the push to talk switch makes Pin 8 ground with BRT(Q802), PLL IC works
under transmit status.
The programmable divider output fed to the phase detector for compare with the 2,5KHz
reference frequency IC301. See table 1 for actual input and divide ratio on all channels.
4-3-5. Phase Detector and VCO Control
The phase detector is a digital phase comparator witch compares the phase of the reference
signal with programmable divider output square waves and develops a series of pulses whose dc level
depends on the phase error of each signal.
The phase detector pulse output is fed to an active low pass filter and RC low pass filter output
signal of IC301 is filtered and fed to varicap D301 control the VCO frequency.
4-3-6. Transmitter / Receiver Buffer AMP
Output signal of Q301 is fed into the buffer amplifier Q302, L302 to generate TX carrier
frequency and 1’st local frequencies.
ble Divider and Its Control
TTI 2007-02-23
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