Sangean DT-120 User manual

DT-120
FM STEREO/AM/TV RADIO
CONTENTS
Specification ………………………………………………………………………………………………………2-3
Block Diagram ………………………………………………………………………………………………………4
Alignment Instructions…………………………………………………………………………………………………5-8
Test Points Diagram…………………………………………………………………………….……….……………9
PCB Top View…………………………………………………………………………….……….……………10
PCB Bottom View.………………………………………………………………………….……..………..…..11
Wiring Diagram..….………………………………………….………………….….……………..……….12
Troubleshooting Flow Chart..….………………………………………….……………….….……………..……13-14
Electrical Parts List………………………………………………………………………………....……………15-16
Mechanical Parts List……………………………………………………………………….………….…………….17
Exploded Views.…………………………………………………………………………….…………….……………18
IC Circuit Block Diagram…………………………………………..…………….………………………………19-20
IC and Transistor Voltage Chart….……………………………..…………………………….…………………21-22
Semiconductor Lead Identifications……………………………………………………………………..……..…23
Schematic Diagram………………………………………….……………………………………………………24

SPECIFICTION.
FM ELECTRICAL PERFORMANCE
Model : DT-120 (EUR) Brand: Temp: ℃ R.H.: % Date : 2006/04/27
Condition Value Test No.
Test Item Input Output Freq. Nom. Lim. 1. 2. Unit
Min. 87.5
Tuning Range S/N=6dB Max. 108.0
MHz
Intermediate Freq. S/N=6dB 10.7 ±0.05 MHz
90 MHz 12 18
98 MHz 12 18
Max. Sensitivity S/N=6dB 106 MHz 12 18 dBu
90 MHz 18 24
98 MHz 18 24
Usable Sensitivity S/N=30dB 106 MHz 18 24 dBu
Image Rejection S/N=6dB 106 MHz 14 dB
I.F. Rejection S/N=6dB 90 MHz 50 dB
3 db Limiting 60 dBu 18 24 dBu
Min. Output 60 dBu Vol=min 0.2 0.4 mV
Auto.Scan.Stop.Sens. 18 24
dBu
Stereo Separation
(1kHz) 24 18
dB
S/N Ratio(22.5kHz) 45 36 dB
Current Consumption
(22.5HzDev.Modulatio
n 400Hz/DBB) R.O. 35 45
mA
Am. Suppression 32 26 dB
100 200
Hz
Audio fidelit
y
75KHz
dev. (-3dB W/ 50us
Pre Emphasis) 10K 8K
Hz
Output Power
(45HzDev.Modulation
400Hz/DBB) VRmax 1 0.5
mW
DBB Action
ON / OFF(100Hz) R.O. 9 6
dB
T.H.D.(45kHz dev.)
60 dBu
1.5 3 %
Over Load Capacity 10%T.H.D
98 MHz
110
dBu
Lowest Batt. Volt. 60 dBu 98MHz 1.05 1.10
V
Supply Voltage：DC 1.5 V R.O.： 0.05 mW Load： 16 Ω Modulation：1kHz/22.5kHz Dev.
Remark： ( )首件產品 ( )客戶抽測：
( )成品 ( )例行抽測 ( )業務樣品：
( )半成品 ( )新機種 ( )工程變更：
Approved By Released/Tested By
2

SPECIFICTION.
AM ELECTRICAL PERFORMANCE
Model : DT-120 (EUR) Brand: Temp: ℃ R.H.: % Date : 2006/04/27
Condition Value Test No.
Test Item Input Output Freq. Nom. Lim. 1. 2. Unit
Min. 522
Tuning Range S/N=6dB Max. 1629
KHz
Intermediate Freq. S/N=6dB 450 ±2 KHz
603 KHz 54 58
999 KHz 52 56
Max. Sensitivity S/N=6dB 1404 KHz 52 56 dBu
603 KHz 60 64
999 KHz 58 64
Usable Sensitivity S/N=20dB 1404 KHz 56 62 dBu
Image Rejection S/N=6dB 1404 KHz 36 30 dB
I.F. Rejection S/N=6dB 603 KHz 40 34 dB
Selectivity(±9KHz) S/N=6dB 26 18
dBu
Bandwidth (-6 dB) S/N=6dB 4-12
KHZ
Auto.Scan.Stop.Sens. 63 70
dBu
S/N Ratio 36 28 dB
Current Consumption R.O. 35 45 mA
50 100
Hz
Freq. Response
(-6dB)
2300 2000
Hz
Output Power
.(MOD60%) VRmax 1 0.5
mW
Lowest Batt. Volt. . 1.05 1.10
V
T.H.D.(MOD60%)
74 dBu
3 5 %
Over Load Capacity 10%T.H.D
999 KHz
100 90
dBu
A. G. C. F. O. M. 100dBu 46 40
dB
Whistle Modulation 74 dBμ
/m 2IF/3IF
15 %
Supply Voltage：DC 1.5 V R.O.： 0.05 mW Load： 16 Ω Modulation：400Hz/30%Mod.
Remark： ( )首件產品 ( )客戶抽測：
( )成品 ( )例行抽測 ( )業務樣品：
( )半成品 ( )新機種 ( )工程變更：
Approved By Released/Tested By
3

Q6
CF1
L IN
Q13
D2 / L2D3 / L3
CF2 CF3
D1, Q1
AM RF
switch circuit
Q10
Q2 / Q11 / Q12
DBB CONTROL R O/P L IN IF IN
LCD DISPLAY
Earphone
JK1
X1
SW10 BAND SW7 Tuning up SW4 VOL. up
POWER SW
MEMORY
FM RF AMP
FM OSCFM RF
FM AM
ANT1, CT1,
R IN
LOW BST
FM QUAD
AM/FM BAND
MUTE CIRCUIT
R IN L O/P OSC IN
75KHz
X. TAL
SW9 DBB
HOLD SW
SW3
SW2
KEY
SW401 - 405
POWER CONTROL
IC3 AN7504 SB
IF FILTERIF FILTER
IC1 TA2142FN
AM/FM TUNER
D1 / L1
BATTERY x 1
SW8 Tuning DOWN
IC1 VCC CONTROL
POWER AMP
AM OSC
LPF
Q4, Q5, L5
1.5V
SW6 VOL DOWN
VOL. Control
u-COM IC
TC9349FG
POWER CONTROL
BLOCK DIAGRAM
4

ALIGNMENT INSTRUCTIONS
1. ALIGNMENT FOR TUNING CAPACITOR VOLTAGE RANGE
a. Required Instruments：
Signal Generator
SSVM
b. Alignment Procedure
Mode Adjustment Procedure
(1) Set the power switch to ON.
(2) Connect a SSVM to TP1.
(1) Tune FM to 108 MHz.
FM L2
(2) Adjust L2 to have a reading of 7.8V on the SSVM.
c. Instrument Connection
L2
TP1
SSVM
5

2. ALIGNMENT FOR FM SENSITIVITY
a. Required Instruments：
Signal Generator
SSVM
b. Alignment Procedure
Mode
Adjustment
Procedure
(1) Set the power switch to ON.
(2) Connect a SSVM to the HEAD PHONE JACK O/P.
(3) Connect the output of the FM signal generator to the test point (TP5).
(4) Set FM to 106MHz.
FM L3
(5) Adjust L3 for maximum audio output.
c. Instrument Connection
L3
Signal Generator
TP5
6pF
To Speake
r
HEAD PHONE JACK O/P
SSVM
6

3. ALIGNMENT FOR TUNING CAPACITOR VOLTAGE RANGE
a. Required Instruments：
Signal Generator
SSVM
b. Alignment Procedure
Mode Adjustment Procedure
(1) Set the power switch to ON.
(2) Connect a SSVM to TP1.
(1) Tune AM to 1629 KHz.
AM L1
(2) Adjust L1 to have a reading of 6.1V on the SSVM.
c. Instrument Connection
L1
TP1
SSVM
7

4. ALIGNMENT FOR AM SENSITIVITY
a. Required Instruments
AM Signal Generator
SSVM
b. Alignment Procedure
Mode Adjustment Procedure
(1) Turn on the radio.
(2) Connect a SSVM to the speaker H.P JACK and GND terminals.
(3) Connect an AM signal generator together with standard loop dummy antenna and
feed 30% modulated signal to the AM ferrite bar antenna (ANT1).
(4) Tune the generator frequency to 1404 KHz.
(5) Tune the AM frequency to 1404 KHz and adjust CT1 to have a max reading on SSVM.
(6) Return the generator frequency to 603 KHz.
(7) Tune the AM frequency to 603 KHz and adjust ANT1 to have a max reading on SSVM.
AM CT1
ANT1
(8) Repeat (4) to (7) as necessary to minimize tracking error.
c. Instrument Connection
ANT1
CT1
60 cm
Loop Antenna
AM Signal Generator
The radio is located
perpendicularly to
the Loop Antenna
GND
DVM
HEAD PHONE JACK O/P
8

Gray = Bottom layer
Yellowish brown = Top layer
TEST POINTS DIAGRAM
9

PCB TOP VIEW
10