Fisher CR-5125 - Page 12

ELECTRICAL
ADJUSTMENTS
(Continued)
4. Then, adjust the potentiometer (P103) until the output Jevel
of 1 V on the LINE OUT is obtained on the VTVM keeping
the unit in the above condition.
RIGHT CHANNEL
Connect an audio signal generator to the right channel LINE
IN, a VTVM to the test point (TP201), anda VTVM to the
right channel LINE OUT. Then, adjust the right channel
INPUT Level Control and the potentiometer (P203) for the
right channel by following the same procedure as for the left
channel.
PLAYBACK GAIN & METER LEVEL ADJUSTMENT
LEFT CHANNEL
1. Connect a VTVM to the left channel LINE OUT as
illustrated. Then, insert a test tape for the DOLBY Level
calibration (Example: TEAC MTT-150) into the cassette
compartment.
LINE OUT
PLAY BACK
VTVM (1V)
ND 47 k-ohm
Dummy Load
2. While the test tape is being played back, adjust the
potentiometer (P107) until the output level becomes 71 V on
the VTVM.
3. Keeping the unit in the playback mode, adjust the
potentiometer (P102) until the pointer of the left channel
Meter swings to +3VU (DOLBY mark position) as
illustrated.
[4] FISHER
INPUT LEVEL /OUTPUT ZEVEL
RIGHT CHANNEL
Connect a VTVM to the right channel LINE OUT. Then,
adjust the potentiometers (P207 and P202) for the right
channel by following the same procedure as for the left
channel.
DOLBY FM SENSITIVITY ADJUSTMENT
LEFT CHANNEL
1. Connect an audio signal generator and an attenuator to the
left channel LINE IN, and a VTVM to the left channel LINE
OUT as illustrated.
Audio Signal
Generator
1 kHz
1V RMS
RECORD
Attenuator
200mV (—14 dB)
VTVM (1V)
Dummy Load
Left Channel Output = Right Channel Output
2.
Set the
DOLBY
FM
Switch
to
ON,
and
the
Monitor
Switch
to
SOURCE.
Then,
feed
the
1
kHz
signal
from
the
audio
signal
generator
at
200
mV
(—14
dB)
to
the
unit
with
the
DOLBY
FM
Sensitivity
Control
set
to
the
maximum.
3. Read the output level on the VTVM.
RIGHT CHANNEL
Feed
the
1
kHz
signal
from
the
audio
signal
generator
at
200
mV
(—14
dB)
to
the
right
channel
LINE
IN
and
adjust
the
potentiometer
(P201)
until
the
output
level
of
right
channel
becomes
identical
to
the
left
channel
output
level
on
the
VTVM.
LINE IN—;