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a.
Connect
the
895A
to
TP7,
using
+
OUTPUT
as
common.
b.
Set
FUNCTION
switch
to
ON
and
RANGE
switch
to
1000.
c.
Set the voltage
dials as
shown
in
Figure
4-8,
and
verify
the
voltages are as indicated.
VOLTAGE
DIALS
I
1
341
343A
200.000
200.0000
300
to
360
500.000
500.0000
360
to
420
700.000
700.0000
4.1
0
to
480
800.000
800.0000
450
to
520
900.000
900.0000
450
to
520
1000.000
1000.0000
470
to
540
Figure
4-8.
HIGH
VOLTAGE POWER
SUPPLY
OUTPUT VOLTAGES
FAULT ANALYSIS
If
the high voltage
power
supply
voltages
are
not
correct,
check
diodes
CR53
and.
CR54,
capacitors
€55
through €58,
and
transformer
Tl.
4-57.
BETA
STRING
4-58.
The
following
sequence of
tests
is
intended
to
detect gross
errors in
the beta
string resistors
or
their
switching
patterns.
341
343A
VOLTAGE
DIAL
TESTED
89
5
OUTPUT
VOLTAGE
INCREMENT
341
343
RANGE NULL
@
0.0000
00.00000
100
TVM
IGv
Ogj.OOOG
00.00000
10
TVM
1v
o
o
o
o
0000000
1
TVM
0.1 v
00.0000
00.00000
1
.1
10
mv
00.00000
1
.01
1
.0
mv
00.00000
1
1
MV
100
uv
00.00000
1
IGOuV
10
uv
Figure
4-9.
BETA
STRING SWITCHING
REQUIREMENTS
FAULT
ANALYSIS
If
the beta
string
switching
is
incorrect,
it is
likely
that
one
or
more
beta
string resistors,
has
changed
value.
Check
for defective
resis-
tors,
and perform
the zero
output adjustments
and
beta
string calibration,
paragraphs 4-65
and
4-66 (paragraphs
4-74, 4-75, 4-79,
and
4-80
for
the
Model 343A).
4-59.
PANEL
METER
4-60.
The
following
test verifies
proper operation of the
meter
circuit
by
comparing
full-scale
meter
readings to
instrument
output
voltages.
a.
Set the
FUNCTION
switch to
METER
VOLTAGE.
b.
Set
RANGE
switch
to
10
and
voltage'
dials
to
10.00000 (10.000000
on Model
343A).
The
instru-
ment
meter should
indicate
10
volts
±5%.
a.
Connect
the
895A
to the
OUTPUT
terminals.
Set
the
895
A
to
TVM
mode,
with readout
dials at
zero.
b.
Set
the
Model
341A/343A
controls
as
follows:
FUNCTION
RANGE
Voltage
dials
CURRENT
LIMIT
ON
100
Zero
Fully clockwise
c.
Null the
895
A
on
the
100
uV
range.
c.
Set
RANGE
switch
to
100 and
voltage
dials
to
100.0000 (100.00000
on Model
343A).
The
instru-
ment
meter should
indicate
100
volts
±5%.
d.
Set
RANGE
switch
to
1000 and
voltage
dials
to
1000.000 (1000.0000
on Model
343A).
The
instru-
ment
meter should
indicate
1000
volts
±5%.
e.
Set
RANGE
switch
to
10
and
voltage
dials
to
10.00000 (10.000000 on Model 343
A).
Set the
Model
341A/343A
and
895A
controls
as
shown
in
Figure
4-9.
The
voltage
increments should
correspond
to the values
shown.
f.
Set
CURRENT
LIMIT
control
maximum
clockwise,
and
connect
the
400
ohm±l%,
1
watt
resistor
to
the
OUTPUT
terminals.
4-13
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