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| АХ-311ВК
Adjustment Procedures
Ш Power Amplifier Idling Adjustment
Left
Channel
R773
R751
(A)
Qi,
1-49)
. Before turning on the power, turn the the semi-fixed
resis-
tors (R751 for L channel and R752 for R channel) of the
power amplifier circuit board fuily counterclockwise.
. Adjust the semi-fiexed resistor (R751
and R752) so
that the voltage
at the following
test points
of the
power amplifier circuit board is within a range of 3 ~ 5
mV after the power is turned on.
L channel:
Measure the voltage between test point (4)
(emitter of Q761)
and output
at the test
point (B).
R channel: Meaure the voltage between test point (C)
(emitter of 0762)
and output at the test
point (D).
Right
Channel
R752
Qi,
. Readjust resistors R751
and R752
about
10 minutes
after the power is turned on (the heatsink temperature
must be sufficiently high) so that the voltage at the test
points becomes 11 mV.
Confirm that the voltage does not vary when the heat-
sink temperature increases further.
Note:
Be sure to perform the measurenent
with the
probes and cabinet of the measuring equipment
separated
from
the
grounding
terminals
of
AX-311BK
or other measuring
equipment.
(No. (2097)
1-7
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