GE 4PE350A3 Instructions Manual page 44

EBI-6351
COLOR CAMERA
STEPS THEREFORE, EXERCISE
EXTREME CAUTION TO PREVENT
ACCIDENTAL SHOCK.
7. Using a high -voltage rated meter or
meter probe, the voltage at the viewfinder
picture tube anode should be between 15 KV
and 16 KV.
8. While monitoring the output high volt-
age and adjusting the raster brightness from
0-200 foot-candles, adjust the Camera power
supply voltage regulator control, R2, to ob-
tain a constant voltage over this brightness
range.
9. The voltage on the emitter of Q2 should
vary between +2 and +8 volts to obtain reg-
ulation over this brightness range.
NOTE
If
it becomes necessary to re-
place a component in the viewfinder
high -voltage power supply, neces-
sitating the removal of the silicone
potting compound, use only General
Electric RTV-615 clear
silicone
potting compound as a replacement.
It
is
available directly from the
General Electric Silicon Products
Department, Waterford, New York.
When ordering, be sure to ask for
the brochure describing this pro-
duct, since gives the methods of
preparing the compound.
Iris Control Servo Amplifier Board,
PL -7782027G2
Refer to Figs. 60 and 61.
1. Operate the lens EXPosure control fully
CW and observe that the iris opens to its
maximum position.
2. Operate the lens EXPosure control fully
CCW and observ:
that the iris closes to its
minimum position.
3. Operation
of
the
EXPosure control
should cause a minimum of hunting in the
system. If hunting is noted, check the setting
of the gain potentiometer, R7, on the servo
amplifier as follows:
a. Turn the EXPosure control fully CW
and observe that the lens iris opens fully;
30
adjust R5, if necessary, until this condition
is reached.
b. Turn the EXPosure control fully CCW
and observe that the lens iris closes to its
minimum position; adjust R2, if necessary,
until the condition is attained.
c. Turn R7 fully CW.
d. Turn the EXPosure control to its
mid -position and no further.
e. Adjust R7 until iris hunting action
stops.
f. Recheck the operation of the EXPo-
sure control and watch for hunting action;
reset R7 slightly, if necessary, to minimize
hunting.
Iris Control Servo Power Supply Board,
PL -7672613
Refer to Fig. 62.
1. Using a 20,000 ohm -per -volt meter,
check the -20 volt d -c supply at J1 -B on the
power supply.
2. Adjust R5 for -20 volts ± 1.0.
3. Check the +20 volt d -c supply at J1 -A,
4. Adjust R10 for +20 volts ± 1.0.
NOTE
Always check the -20 volt supply
first, since
it
is used as a ref-
erence for the +20 volt adjustment.
Intercom Amplifier Board, PL -7781675
Refer to Figs. 63 and 64.
1. Check the -20 volt d -c input to the am-
plifier.
2. If the microphone has little or no out-
put, give Q1 a leakage and beta (gain) check.
3. If the receiver has little or no output,
give Q2 a leakage and beta (gain) check.
4. Check the other components for opens
or shorts.
5. If intermittent operation is encountered,
give the wiring a continuity check from the
receiver and microphone to the telephone
plug.
Registration Control Panel,
PL -7672688G3
Refer to Figs. 65 through 68.