Hum Adjustment; Figure 19-Interior View Of Power Supply - RCA 76-B2 Manual

27
the switch is thrown to the EMG position, the
monitor amplifier power supply furnishes the power
for
the microphone preamplifiers and booster
amplifiers. The monitor amplifier is then used in
place of the program amplifier in the Consolette.
Hum Adjustment
If it becomes necessary to make a hum adjustment
on the Consolette, the following procedure
is
recommended:
Load the microphone lines (nos. 1, 2, 3, and 4)
with 250 -ohm resistors. Set the MASTER control
and the mixer controls (1, 2, 3, and 4 attenuators )
for 67 db or normal gain.
Connect an amplifier
having approximately 60 db gain to the LINE OUT
terminals of the Consolette, then adjust the hum
potentiometers P-1 and P-2 on the Power Supply,
for minimum hum. (The LINE OUT switch must
be set at the REG position and the associated mixer
switches on PROGRAM).
S-3
F- 1
F -2 T-1
C -13
R-7
C -7
T- 2
S -2
P-2
R-3
R-2
R-5
C-5
Figure 19-Interior View of Power Supply