Maintenance - GE 4PE21A1 Instructions Manual

CHANNEL AMPLIFIER
EBI-3641
FOCUS REGULATOR
The focus current regulator, V20, and the focus current regulator
amplifier,
V21, are
used
to
regulate the'focus current used for the various
camera focus
coils.
The range
of
operation
is
large enough for both Vidicon
and Image Orthicon focus coils.
A jumper in the power plug, P17, selects
the range by shunting part
of
the focus coil current through resistor R172
when the high range
is used.
Both V23 and V24
are
used
to
regulate the -105 volts
d -c
bias voltage
obtained from transformer,
Tl.
MAINTENANCE
PREVENTIVE
To
obtain the maximum life and proper operation from the Channel
Amplifier,
a
regular preventive maintenance schedule should
be followed.
1.
Inspection
Look for evidence
of
component overheating such
as,
discoloration
of
resistors
or
wiring. Feel transformer cases for overheating. Check
for buldging sides
or
discolored paint.
Check all oil
filled capacitors
for leakage. Check tubes for low emission
or
noisy operation. Look for
flickering
in the gas type
regulator
tube, V24.
Replace any questionable
component.
2.
Records
Where feasible, operating current and voltage readings
of
tubes
should be recorded
at
regular intervals.
These records provide
an excellent
basis from which
to
predict tube life and plan future tube replacements.
3.
Cleaning
Keep the equipment
as
clean and dry
as
possible.
An air blower
or
brush with long soft bristles, makes
a
very good dust remover. When
a
high pressure air hose
is
used for cleaning, care should be taken
not to
disturb components
or
wiring.
4.
Replacement
of
Components
Before installation
of
replacement
parts, check the circuit for
the cause of
failure. When replacing components, select the proper re-
placement part from
the parts list.
All components
are
listed by symbol
number and have their
G -E
drawing number
and a
complete description
given.
When replacing semi -conductor
diodes, exercise caution not to overheat them,
otherwise the diodes will be damaged.
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