Sony srf m 70 service manual

Page 1

SERVICE MANUAL

pom»
W or;

US Model

Canadian Model

AEP Model
UK Model
E Model

Frequency range FM:
AM:

Scan step FM:
AM:

Antennas FM:
AM:

Output

Power output

SPECIFICATIONS

875-108 MHZ

530-1110 kHz (us. CND model)
531-1.602kHz (AEP. UK. E, lT model)
0.1 MHz (US. CND model)

0.05Ml-lz (AEP. UK. E. IT model)

10 kHz (us. CND model)

9kHz (AEP. UK, E, IT model)
Headphones cord antenna

Buiit~in lerrite bar antenna

Headphones lack (stereo minijack) load impedance 16 ohms
20 mW+20 mW (at 10% harmonic distortion)

Power requirement 3 V DC. two size AAA (H03) batteries

Battery lite
Dimensions

Approx. 18 hrs. with Sony UMA (NU) batteries
Approx. 665 X111! x 303 mm (wlhld)

(2% x 45/a x W. inches)

excl. projecting pans and controls

Weight

Approx. 135 g (5 oz.)

including batteries.

Aocessorles supplled

Stereo headphones (l. vertical-in-theear type)
Belt holder (1)
Arm band (I)

Design and specifications subject to change Without notice.

US. CND. UK model

AEP. E. IT model

12-hours system

24hour system

AM 12: OO=midnight
PM 12: 002noon

0 : 00=rnidnight
12 : 00= noon

IT model :

CND model: Canadian model
Italian model

FEATURES

- AMIFM stereo 2-band PLL synthesized receiver:
- Up to 10 stations can be stored in the desired order.

- Water-resistant.

- Built»in digital clock and stopwatch.

- Countdown timer.

Note on AM tuning intenml

The AM tuning interval diflers depending on the area.

Area

US. CND model

10 kHz

AEP. UK. E. |T model

9 kHz

NOTE ON CHIP COMPONENT REPLACEMENT

0 Never reuse a disconnected chip component.

0 Notice that the minus side of a tantalum
capacitor may be damaged by heat.

AM/FM STEREO 2 BAND
PLL SYNTHESIZEI] RECEIVER

SONE

Page 2

SECTION 1
ELECTRICAL ADJUSTMENTS

AM Section

AM RF signal
generator

Put the lead-wire
/|/ antenna close to
O the set.

30% amplitude
modulation by

400Hz signal

Output level : as low as possible

FM RF signal
generator

60% 0'01 TP
|-> FM ANT
input terminal

:22.5kHz trequency deviation
by 40on signal
Output level :as low as possible

VTVM
m

%% i L
set
'-o

PHONES jack

' Repeat the procedures in each adjustment several times.

and the tracking adjustments should be finally the
trimmer capacitors.

FM FREQUENCY COVERAGE ADJUSTMENT

Adjustment Frequency Reading on Digital
Part. Display voltmeter
L4 108MHz 10V

Note 1 Not use the FM signal generator in this adjustment.

FM TRACKING ADJUSTMENT
Adjust for a maximum reading on VTVM.

CT2 1.3-1, 1.3-2

108MHz 37.5MH2

AM FREQUENCY COVERAGE ADJUSTMENT

Adjustment Frequency Reading on Digital
Part Display voltmeter
L5 1,710kHZ (1,602kHZ) 8V (7.3V)

Note : Not use the AM rf signal generator in this adjustment.

AM TRACKING ADJUSTMENT
Adjust for a maximum reading on VTVM.
CTl L2
1,490kHz (1,395kHz) 580kHz (SZIkHz)

AM iF ADJUSTMENT
Adjust for a maximum reading on VTVMt
T1 450kHz

( ) : AEP, UK. E, [T model

FM VCO Adjustment

Procedure :
FM RF signal Tl
generator FM ANT

input terminal

E w

Carrier frequency : 108MHz
Modulation 2 no modulation
Output level 2 lmV (6MB)

Connect frequency counter to it as shown below.
Tune the set to 108 MHZ.

Adjust RVl for 76 kHzilOO l-lz reading on the
frequency counter.

93.