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'M&
—
UU-f-lw
A15
Rav.
B
&
C
(Icutrumant
Serial
No's
1622A00906
and
greater)
0S45S-66515
Re«.
A
(Instrument
Serial
No's
1622100905
and
below.)
Aa
Ad
A
A
Ag
Ah
A|
Aj
C37,
C38
and
H97
have
been added
and
the value of
A15R59
has
beer'
changed
from 10
kn
to
100
kn
to eliminate
transients
during autoH'angIng
which
causa
inaccurate
"first" readings.
(Instrument
Serial
No's
1622A00906
and
greater.)
R89
has
been
mads
a
"selected" value to
improve
the accuracy
at
1
MHz.
(Instrument
Serial
No's
1622A00101
and
greater.)
C36
and
R96
have been
added
to reduce
offset at
elevated
temperatures, (instrument
Serial
No's
1622A00906
and
greater.)
Relay
K3
has
been changed
to a different
type
to prevent arcing during auto-ranging
when
1000
V
is
applied to the
input.
(Instrument
Serial
No's
1622A00906
and
greater.)
The
values of
potentiometers
R72
and
R75
have been decreased
to
improve
the temperature
stability
of the input amplifier
circuity.
The
value of
resistors
R81 and
R8S
have been
increased
to center the
pots.
Previous values were:
R72, 200; R75,
2 K;
R81,
5.1
1
K;
R85,
562.
These
changes have been
made
on
instrument with
Serial
No's
1622A00906
and
greater.
The
following
component
changes have been
made
to
improve
the down-scale
linearity
of the
RMS
converter:
R17; from
2
kn
to
5 kn.
R23; from
68
kn
to
100 kn. R25; from 25
kn
to
100
kn.
R51; from 100
n
to
200
n.
R52; from 10
kn
to
20
kn. R53: from
5
kn
to
10 kn.
These changes have been
made
on
instruments with
Serial
No's
1
622A051
1
and
greater.
Serial
numbers
1622A01000
and
above. Replaces
0757-0417 (562 Q)
to
Increase
the zero
ad-
justment
range.
Serial
numbers
1622A01806
and above
replaces
5080-9080.
The
new
part
Is
not
hand-selected.
Serial
numbers
1622A01656
and above
replaces
R36: 0698-4450
(324 O)
and R95: 0757-0407
(200
n).
R95
provides
improved
dc compensation.
R36
essentially
improves temperature
sta-
bility.
Serial
numbers
1622A02256
and
above.
Added
as
ac bypass of
CR3.
Al
Serial
numbers
1622A01956
and
above. Replaces
0757-0486
(825
K) to
Increase the offset
adjustment
range.
Am
Serial
numbers
1522A01206
and above
the fallowing
component
changes were
made
to im-
prove
Input amplifier
temperature
stability:
Old
Part
No.
R81: 0698-3382
(5490)
R82: 0698-4308
(16.9
K)
R83
:
0698-4429
(1870)
R85: 0698-4459
(634)
R71
:
See padding
list
as
per Table
6-1.
A|sj
Serial
numbers
1622A03136
and
above.
Improved
specifications
on
U3
and U1
make
the
ex-
panded
offset
adjustment
range
no
longer required.
R18
and R31 were changed from
part
number 0698-4540
(412 K)
to
732
K
to reduce
this
range
and improve
stability.
^0
R66 was
changed from
200 K
(0683-2045)
to
16
K
(0683-16351
to
improve
the
first
reading
after switchirtg
from
the
10V
range
to
the
1
00 V
range.
C33
was
changed from
.1
*iF
(01
60-3581
)
to
.22
/iF
(0160-3966)
to
improve accuracy
at
30
Hz.
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