Manual Backdating Changes - HP 3400A Operating And Service Manual

Model 3400A
Appendix
C
S
MANUAL BACKDATING CHANGES
MODEL
3400A
RMS VOLTMETER
This
manual backdating sheet
makes
this
manual
applicable to
earlier instru-
ments.
Instrument-component values
that differ
from
those
in the
manual,
yet
are
not listed
in
the
backdating sheet,
should
be replaced using
the
part
number
given
in
the
manual.
Instrument
Serial
Prefix
Make Manual Changes Instrument
Serial
Prefix
Make Manual Changes
322-.401-.528- and 714-
1,
14
and
8
thru 12
322- or
401-00351
thru
00700
1
thru 5,7 thru
12,
and
14
401-00701 thru 02125 1,3,4,5,
14,
and
7
thru
12
401-02126
thru
03025
1,4,5, 14,
and
7
thru
12
528-
1,5,
14,
and
7
thru
12
714-
1,
14,
and
6
thru
12
714-06526
thru
06925
Note
#1
714-06926
thru
07925
1,
14
and
8
thru
12
806-07926 thru 08125 8 thru 12
and
14
806-08126
thru 08614
9,10,11,12,14
806-08615
thru 09325
10,11,12,14
806-09325
thru 11525 11,12,
14
952-11526 thru 12125 12,14
979-12126 thru
0979A13725 13
All 15
CHANGE
#1
Figure 6-3, and"
Replaceable Parts: Substitute
Figure
C-l
for
Figure 6-3 and replace any
component according
to
Table C-l.
Section
IV,
Theory
of
Operation:
Serials prefixed 322-, 401,
528- and 714-
with
chopper amplifier
board 03400-66504)
does
not
have an emitter follower stage prior
to
the
demodulator.
In
Section IV
delete
any reference
to
emitter follower Q604, and change reference designator
Q605 and
Q606
to
Q604 and Q605 respectively.
CHANGE
#2
Delete C305, -hp- Part No.
0160-0763, on Figure 6-1 and
in
Table 7-1.
Add
a
dashed
capacitor
in
parallel with R301 thru
R304 and R306.
REASON:
This
capacitance obtained by connecting a
wire
from
R301 and C302
junction to
a blank switch lug
near
R306 and
R308
junction.
CHANGE
#3
Change Q405
to
-hp- Part No. 1850-0099, and CR401
to
-hp- Part No. 1910-0016.
NOTE:
Both
Q405
and
CR401 should be replaced with
components
listed
in
Table
7-1
if
either
component
fails
as bias
on Q405
is
a function of both.
CHANGE
H
Change Figure 6-4,
Power Supply Schematic, A7, to the following:
<2,<
90 VAC
+77V 90 VAC
TO TO
TO
A6-3
A6-4 A6-5
>20>
•—«**—•
8 ^~
*
CIA
1
+
+
1
C
,B
^
§
40
^
1
IR704
•36K
;R705
'20K
C-l