Sensitivity Switch Calibration - HP 333A Operating And Service Manual

Model 333A/334A
SENSITIVITY
Switch
Position 4
Position 3
Position 2
Position 1
C.
d.
e.
f.
g*
h.
TEST OSCILLATOR ADJUST
OUTPUT (Increase) FOR 9 mV
+lo
dB
ac4
+20 dB s2c3
+30 dB s2c2
+40 dB
ac1
SENSITIVITYVERNlER..
. . . . .
MIN.
SENSITIVITY.
. .
.1 step counterclochise
METER RANGE
.
,
.
.
,
. .
SET LEVEL
MODE..
. . . . . . . . . . . . .
MANUAL
FREQUENCY RANGE
. . . . . . . .
X1K
Frequency Dial.
. . . . . . . . . . . .
60
Turn slot on trimmer capacitor C3 parallel
with side casting of instrument.
Set test oscillator frequency to 60 kHz, and
adjust amplitude for indication of +2 dB on
333A/334A meter.
Set 333A/334A COARSE and FINE BALANCE
controls
to
center of range.
Set 333A/334A FUNCTION switch to
DIS-
TORTION.
Adjust
test
oscillator frequency vernier con-
trol and C3 for definite null indication on
meter of 333A/334A. Reduce METER
RANGE setting as necessary to maintain
on-scale reading.
Observe electronic counter indication. If
test oscillator frequency is not between
57 kHz and 63 kHz, 333A/334A frequency
dial is
out o f tolerance. Follow steps be-
low to bring frequency d i a l within tolerance:
Set 333A/334A controls as in step b.
Set test oscillator frequency for elec-
tronic counter indication of 60.00 H I ,
and adjust amplitude for indication of
+2 dB
on meter of 333A/334A.
Set 333A/334A COARSE and FINE BAL-
ANCE
controls to center of range.
Adjust 333A/334A frequency dial vernier
control for definite null.
Remove knob from frequency dial. Do
not change tuning capacitor, C4, setting
Loosen retaining screws in frequency
dial plate, and slip dial until 60 i s dir-
ectly under mark on indicator. Be
careful not to change C4 setting.
Tighten retaining screws and replace
knob.
5-30. SENSITIVITY SWITCH CALIBRATION.
a . Connect test oscillator to 333A/334A ae
shown in Figure 5-1.
NOTE
Selector positions for the SENSI-
T M T Y selector will be referred to
as follows: MIN = Position 1, next
step = Position 2, etc., to MAX =
Position
6.
b.
C.
d.
e.
f.
8.
Section V
Set Distortion Analyzer controls as follows:
FUNCTION..
. . . . . . . .
SETLEVEL
METER RANGE
. . . . . . .
0.01 VOLTS
SENSITIVITY
. . . . . . . . . .
Position 5
SENSITIVITY VERNIER
. . . . . . .
MAX.
Set test oscillator frequency
to
400 Hz,
ad-
just amplitude for indication of 9 mV on
333A/334A meter.
Set
a
reference on meter of test oscillator
and use amplitude control to maintain set
reference whenever frequency of oscillator
is varied.
Set test oscillator frequency to 100 kHz.
Adjust S2C5 for 333A/334A meter indication
of 9 mV.
Set 333A/334A SENSITIVITY switch to each
position listed in Table 5-6, and increase
test oscillator output by 10 dB f o r each re-
spective decrease
in
SENSITIVlTY switch
position. Adjust appropriate capacitor for
333A/334A meter indication of 9 mV a t each
setting.
NOTE
When switching the SENSITMTY
positions,
be
careful not to move
SENSITIVITY VERNIER control
from MAX. position.
5-31. ADJUSTMENT OF FACTORY SELECTED
COMPONENTS.
5-32. Certain components in the Model 333A/334A
are individually selected to compensate for
va.rying
circuit parameters. These components are designated
l q r an asterisk
(*) on the schematic and in the parts
list, and the typical
value i s
shown
describes the function of the factory selected compo-
nents
and lists their value
ranges.
Table 5-7
5-33, T R O U BLES
H
0 OTI N G PR 0 CEDU R E t .
5-34. This section contains procedures designed to
assist
in the isolation of malfunctions, These pro-
cedures are based on
a
systematic analysis of the
instrument circuits in an effort to localize the prob-
Table
5-6.
Sensitivity Switch Calibration
5-11