Sony STR-V 25 - Page 6

STR-V25
STR-V25
Signal Indicator Level Adjustment
Setup:
MODE switch:
FREQUENCY COVERAGE ADJUSTMENT,
TRACKING ADJUSTMENT and
IF ALIGNMENT
VCO Adjustment
MONO
A)
Regular
Method
The
front-end
section
has
been
carefully
FM
rf
adjusted
at
the
factory,
so
the
adjustment
is
signal
unnecessary
in
the
field.
generator
Setting:
FRONT-END SECTION
MODE
switch:
:
Procedure:
FM rf signal
FM antenna
generator
terminal
Carrier frequency: 98MHz
Modulation: 400 Hz, 75kHz deviation
(100%)
Output level: 1mV (60 dB)
Procedure:
Tune the set to 98 MHz and adjust RT802 so
that all signal elements light up. (See figure
below.)
—
co = ae green lamp
lights up
5
4 2 3 4
FM antenna
terminal
Carrier frequency: 98MHz
Modulation: 400 Hz, 75 kHz deviation
(100%)
1mV (60 dB)
Output level:
4
FM Muting Level Adjustment
Setting:
MODE switch: STEREO
MUTING switch: ON
Procedure:
FM rf signal VOM
generator fac range)
tuner board
frequency counter
1.
2. Adjust RT101 for 76 kHz + 100 Hz on the
counter.
Tune the set to 98 MHz.
FM Stereo Separation Adjustment
FM stereo
signal generator
output channel
L-CH L-CH (A)
Adjust
RT102 for
minimum
reading
VTVM
connection
VTVM
Setting:
reading
(dB)
MODE switch: STEREO
MUTING switch: ON
FM antenna REC OUT
terminal
B) Simple Method
Carrier frequency: 98MHz
Modulation: 400 Hz, 75 kHz deviation
(100%)
10 wV (20 dB)
Procedure:
1. Tune the set to the FM stereo broadcasting
signal.
Output level:
Procedure:
1. Tune the set to 98 MHz.
2.
Turn
RT801
and
stop
it
just
when
the
VOM
indication
suddenly
decreases.
2. Turn RT101 clockwise or counterclockwise and
memorize the lighting-up range of the stereo
lamp.
FM rf stereo
Signal
ma
generator
©
©)
Adjust
RT102 for
minimum
reading.
3. Receive a signal stronger than the muting level.
Confirm that the ACUTE SERVO LOCK lamp
(green) lights up. (See figure below.)
3. Secure RT101 at the center of the lighting-up 0.01 HF
range of both turns as shown below.
center of lighting-up ranges
FM antenna
terminal
REC OUT
lighting-up range
L-CH Stereo separation: (A) —
R-CH Stereo separation: © —
The separations of both channels should be
equal.
ry
LOCKED
ACUTE SERVO LOCK
Carrier frequency: 98 MHz
Output level: 1 mV (60 dB}
Modulation:
Audio (400 Hz}: 33.75 kHz deviation (45%)
Pilot (19kHz): 7.5kHz deviation (10%)
The green lamp at the
center lights up.
=7— —8—