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ICF-C273
SERVICE MANUAL
FM/AM PLL SYNTHESIZED CLOCK RADIO
SPECIFICATIONS
Australian Model
Ver 1.0 2004.03
9-877-642-01
2004C02-1
© 2004.03
Sony Corporation
Personal Audio Company
Published by Sony Engineering Corporation
Time display
12 hour
Frequency range
Band
Band
Channel step
FM
87.5-108 MHz
0.05 MHz
AM
531-1 602 kHz
9 kHz
Speaker
Approx. 6.6 cm (2
5
/
8
in.) dia. 8
Ω
Power output
200 mW (at 10% harmonic distortion)
Power requirements
230 V AC, 50 Hz
Dimensions
Approx. 173 x 57.2 x 133.5 mm (w/h/d)
(6
(6
7
/
8
x 2
3
/
8
x 5
3
/
8
in.) incl. projecting parts and controls
Mass
Approx. 630 g (1 lb 6.2 oz)
Design and specifications are subject to change without notice.
ICF-C273
2
TABLE OF CONTENTS
Specifications ........................................................................... 1
1. GENERAL
Location and Function of Controls .................................... 3
2. DISASSEMBLY
2-1. Switch Board, Cabinet (Upper) .................................. 6
2-2. Alarm Board, jog Board .............................................. 7
2-3. Main Board ................................................................. 7
2-4. Trans Board ................................................................ 8
2-2. Alarm Board, jog Board .............................................. 7
2-3. Main Board ................................................................. 7
2-4. Trans Board ................................................................ 8
3. ELECTRICAL ADJUSTMENTS
............................. 9
4. DIAGRAMS
4-1.IC Block Diagrams ..................................................... 11
4-2.Block Diagrams ......................................................... 12
4-3. Printed Wiring Board –Main section (1/2)– ............. 13
4-4. Printed Wiring Board –Main section (2/2)– ............. 14
4-5. Schematic Diagram –Main section (1/2)– ................ 15
4-6. Schematic Diagram –Main section (2/2)– ................ 16
4-2.Block Diagrams ......................................................... 12
4-3. Printed Wiring Board –Main section (1/2)– ............. 13
4-4. Printed Wiring Board –Main section (2/2)– ............. 14
4-5. Schematic Diagram –Main section (1/2)– ................ 15
4-6. Schematic Diagram –Main section (2/2)– ................ 16
5. EXPLODED VIEW
5-1.Cabinet (Upper) Section ............................................ 17
5-2.Cabinet (Lower) section ............................................ 18
5-2.Cabinet (Lower) section ............................................ 18
6. ELECTRICAL PARTS LIST
................................... 19
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK
0
OR DOTTED LINE WITH
MARK
0
ON THE SCHEMATIC DIAGRAMS AND IN THE PARTS
LIST ARE CRITICAL TO SAFE OPERATION.
REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE
PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR IN
SUPPLEMENTS PUBLISHED BY SONY.
REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE
PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR IN
SUPPLEMENTS PUBLISHED BY SONY.
• HOW TO CHANGE THE CERAMIC FILTER
This model is used two ceramic filters of CF2 and CF3.
You must use same type of color marked ceramic filters in
order to meet same specifications.
Therefore, the ceramic filter must change two pieces together
since it's supply two pieces in package as a spare parts.
You must use same type of color marked ceramic filters in
order to meet same specifications.
Therefore, the ceramic filter must change two pieces together
since it's supply two pieces in package as a spare parts.
mark
mark
CF3
CF2
no mark
blue
orange
black
white
10.70MHz
10.67MHz
10.73MHz
10.64MHz
10.76MHz
Mark
Center
frequency
ICF-C273
3
SECTION 1
GENERAL
LOCATION AND FUNCTION OF CONTROLS
This section is extracted from
instruction manual.
instruction manual.
AC power cord
VOLUME
There is a tactile dot beside volume
to show the direction to turn up the
volume.
There is a tactile dot beside volume
to show the direction to turn up the
volume.
Jog lever
FM wire antenna
The PRESET TUNING 3 button has
a tactile dot.
a tactile dot.
ICF-C273
4
Setting the Clock and Date
1 Plug in the clock radio.
The display will flash “AM12:00” or “0:00”.
2 Press CLOCK for a few seconds.
You will hear a beep and the year will start to flash in the display.
3 Press Jog lever v (up) or V (down) until the correct year appears in the
display.
4 Press ENTER/BRIGHTNESS.
5 Repeat steps 3 and 4 to set the month, day, hour, and minute.
5 Repeat steps 3 and 4 to set the month, day, hour, and minute.
After setting the minute, press ENTER/ BRIGHTNESS to start the
counting of the seconds, and you will hear two short beeps.
counting of the seconds, and you will hear two short beeps.
• To set the current time rapidly, hold down Jog lever v (up) or V
(down).
• The clock system varies depending on the model you own.
12-hour system: “AM 12:00” = midnight
24-hour system: “0:00” = midnight
24-hour system: “0:00” = midnight
• In step 5, when you press ENTER/BRIGHTNESS after the minute
setting to activate the clock, the seconds start counting from zero.
• When the alarm setting mode is entered, the clock cannot be set.
To display the year and date
Press SNOOZE/DATE/SLEEP OFF once for the date, and within 2
seconds press it again for the year.
The display shows the date or year for a few seconds and then changes
back to the current time.
seconds press it again for the year.
The display shows the date or year for a few seconds and then changes
back to the current time.
To change the display to the daylight saving time
(summer time) indication
(summer time) indication
Press D.S.T./SUMMER T.
“
” is displayed and the time indication changes to summer time.
To deactivate the summer time function, press D.S.T./SUMMER T.
again.
again.
To set the brightness of the backlight
If you cannot see the display clearly, press and hold ENTER/
BRIGHTNESS to set the desired brightness (high, middle or low).
BRIGHTNESS to set the desired brightness (high, middle or low).
Changing AM (MW) Channel Step
The AM (MW) channel step differs depending on area. The channel step
of this unit is factory-set to 9 kHz or 10 kHz to change the setting as
shown below to be able to listen to the radio.
of this unit is factory-set to 9 kHz or 10 kHz to change the setting as
shown below to be able to listen to the radio.
Channel step
9 kHz
1 Plug in the clock radio.
Press OFF/ALARM RESET to turn off the power.
2 While holding down OFF/ALARM RESET, keep pressing ON/BAND
for more than 5 seconds.
The AM (MW) channel step will be changed.
If you proceed to step 2 again, the channel step changes again.
The AM (MW) channel step will be changed.
If you proceed to step 2 again, the channel step changes again.
Notes
• When the AM (MW) channel step is changed, the preset stations for
AM (MW) will be initialized.
• When the AM (MW) channel step is changed, the FM channel step also
will be changed.
Operating the Radio
—Manual Tuning
—Manual Tuning
1 Press ON/BAND to turn on the radio.
The display shows the band and frequency for a few seconds and then
changes back to the current time.
changes back to the current time.
2 Press ON/BAND repeatedly to select the desired band.
Each press changes the band as follows:
t AM t FM1t FM2
When using FM1 or FM2 preset mode, you may listen to the radio on
either mode. (See “Presetting Your Favourite Station”.)
either mode. (See “Presetting Your Favourite Station”.)
3 Use TUNING + or – to tune into the desired station.
The FM channel step is set to 0.05 MHz* and the AM (MW)
channel step is set to 9 kHz.
channel step is set to 9 kHz.
* The FM frequency display is raised or lowered by a step of 0.1 MHz.
For example, frequency 88.00 and 88.05 MHz is displayed as “88.0
MHz.”
MHz.”
Two short beeps sound when the minimum frequency of each band is
received during tuning.
received during tuning.
4 Adjust volume using VOLUME.
• To turn off the radio, press OFF/ALARM RESET.
• To listen with an earphone, connect the earphone to the v (earphone)
• To turn off the radio, press OFF/ALARM RESET.
• To listen with an earphone, connect the earphone to the v (earphone)
jack. The speaker is deactivated when an earphone is connected.
• To check the station being received, press TUNING + or – or ON/
BAND lightly. The display shows the band and frequency for a few
seconds and then changes back to the current time.
seconds and then changes back to the current time.
Improving the Reception
FM:
Extend the FM wire antenna fully to increase
reception sensitivity.
reception sensitivity.
AM (MW):
Rotate the unit horizontally for optimum
reception. A ferrite bar is built in to the unit.
reception. A ferrite bar is built in to the unit.
Do not operate the unit over a steel desk or metal surface, as this may lead
to interference of reception.
to interference of reception.
Presetting Your Favourite Station
—Preset Tuning
—Preset Tuning
You can preset up to 10 stations in FM (5 stations in FM1, 5 stations in
FM2), and 5 stations in AM.
FM2), and 5 stations in AM.
Presetting a Station
1 Follow steps 1 to 4 in “Operating the Radio” and manually tune into the
station you wish to preset.
2 Hold down the desired STATION•SELECT/PRESET button
until you hear two short beeps.
Example: To preset AM 1 260 kHz onto preset 2 button.
Example: To preset AM 1 260 kHz onto preset 2 button.
The display shows the frequency for a few seconds and then changes
back to the current time.
To preset another station, repeat these steps.
To change the preset station, tune into the desired station and hold
down the PRESET TUNING 1 to 5 button. The new station will
replace the previous station on the preset button.
back to the current time.
To preset another station, repeat these steps.
To change the preset station, tune into the desired station and hold
down the PRESET TUNING 1 to 5 button. The new station will
replace the previous station on the preset button.
Tuning into a preset station
1 Press ON/BAND to turn on the radio.
2 Press STATION•SELECT/PRESET
2 Press STATION•SELECT/PRESET
where the desired station is stored.
3 Adjust volume using VOLUME.
After a few seconds, the display will return to the current time but the
preset button number will remain.
preset button number will remain.
Setting the Alarm
You can choose from two types of alarm, Radio or Buzzer.
The alarm will come on at the same time everyday.
The factory setting alarm time for the radio and buzzer is 12:00am or
0:00.
The alarm will come on at the same time everyday.
The factory setting alarm time for the radio and buzzer is 12:00am or
0:00.
Notes
• Set the current time before setting the alarm.
• Radio reception is interrupted while the alarm time is being set.
• Radio reception is interrupted while the alarm time is being set.
To set the Alarm Time
1 Press and hold ALARM A or ALARM B for a few seconds.
After one beep, the hour flashes in the alarm display.
2 Press Jog lever v (up) or V (down) to select the hour.
To set the hour rapidly, hold down Jog lever v (up) or V (down).
3 Press ENTER/BRIGHTNESS.
After one beep, the minutes flash on the alarm display.
