Maintenance; Parts List - GE 4PE21A1 Instructions Manual

EBI-3527B
POWER SUPPLY
In
this unit the gain
is very
high, in the
order
of
several thousand. Additional
reg-
ulating action is accomplished
by
having
the
control grid
of
V5
connected into the
divider
network at
V5
-E1.
When
the out-
put voltage
decreased,
the
grid
of
V5A
went
more negative with
respect
to the
cathode of V5A,
causing the plate
to go
positive, thereby slightly increasing the
reg-
ulating effect at
the
grids
of
V1
-V4.
MAINTENANCE
To
assure
continuous
and
satisfactory
operation
of
the Power Supply,
a
regular
maintenance schedule
should
be
set
up.
Check the unit
for over -heating
and
dis-
coloration
of
components. Check the tubes
for emission. Check the voltages at the
tube
sockets against
the tube
socket volt-
age
chart
below. It
should
be
noted that
due to the
feedback nature
of the
regulator
circuit,
a
fault at any given point
in the
circuit
may produce
erroneous
voltage
read-
ings at
any
other
point
of the
circuit.
Clean the unit with an
air
hose
or
soft
brush regularly.
Do
not
disturb
the
leads
PIN
or
components positions.
If a
component
requires replacement,
obtain
its description
from
the
Parts List.
Do
not
replace
a
faulty
component without
first
checking the
cir-
cuit
to
determine
the
cause
of the
failure.
When
a
component has been
replaced,
check
the tube socket voltage against those
shown
in the tube socket voltage
chart
to be
cer-
tain
of
proper
functioning
of the new
part.
Tube Socket
Voltage Chart
The
voltages
below were measured
with
a
20,000 ohm
-per
-volt meter.
TUBE
1
2 3
4
5
6
7
8 9
V1
thru
V4
260*
375** 287
260* 375** 287
fil
fil
V5
fil
fil
260* 280 140 145
V6
260
140
145
fil fil
140 115 84
86
*Will
vary
with load
current
and
line voltage.
**At
nominal line voltage,
117
volts.
PARTS
LIST
Symbol
Description
G
-E Drawing
Cl
thru
C4
C5
4
CAPACITORS
(Paper,
molded
plastic,
±
20%,
400 v d
-c
w.
unless otherwise specified)
Electrolytic, polarized twist prong base;
200
mfd
+100%
-10%, 350 v d
-c
w.
Mallory
Type
FP
with
insulating sleeve.
Electrolytic, polarized twist
prong base;
2000
mfd
+250%
-10%, 15 v d
-c
w.
Mallory
Type
WPO 41.
P
-7772471-P19
P
-7770994-P11