HP 652A Operating And Service Manual page 23

c. Adjust 652A AMPLITUDE and VERNIER controls
for dc null meter indication of7.0 mY.
d. Adjust frequency supply for null indication. Do not
readjust reference supply or 652A AMPLITUDE and
VERNIER controls once null is obtained.
e. Adjusting 652A FREQUENCY RANGE switch and
FREQUENCY dial as necessary, sweep 652A slowly over
frequency range of 1 00 Hz to
will change above or below (or both) the null obtained in
Step d. Record minimum and maximum readings of de null
meter ; difference between these two readings should
indicate a change in level of 652A output no greater than
± 2% (see Table 5·3) verifying flatness specification over
frequency range of 1 00 Hz to 1 MHz.
f.
Repeat Step e over the range 1 0 Hz to 1 MHz. The
difference between de null meter maximum and minimum
readings should indicate a change in level of 652A output
no great e r than ± 3% (see Table 5·3) verifying flatness
specification over frequency range of 1 0 Hz to 1 MHz.
g. Repeat Step e over the range of 1 0 Hz to 1 0 MHz.
The difference between de null meter maximum and
minimum readings should indicate a change in level of
652A output no greater than ± 4% (see Table 5·3) verifying
flatness specification over frequency range of 10 Hz to
1 0 MHz.
h. Perform Frequency Calibration (paragraphs 5·27
througb 5·34) and 1 0 MHz Flatness Adjustments (para·
graph 5·35) if tolerances are not met.
(Amplitude readjusted to a reference on
5·12. Flatness.
the normal output monitor.)
a·. Perform Step 5·1 1a. (Note CAUTION.)
b. Set 652A controls as follows :
FREQUENCY RANGE . .
FREQUENCY dial . . . . . . . . . . . . . . . . . . . . 2
OUTPUT ATTENUATOR . . . . . . . . . . 3.0 V
OUTPUT MONITOR . . . . . . . . . . . . NORMAL
AMPLITUDE and VERNIER . . . . . . . Adjust
for a monitor indication of
3.0 V. (This adjustment is cri·
tical as this will be the refer·
ence level for Steps 5·l 2c
througb h.)
c. Adjust reference supply for null indication on dc null
meter.
d. Set 652A FREQUENCY dial to 1 .
e . Readjust 652A AMPLITUDE and VERNIER controls
for 3.0 V on 652A OUTPUT MONITOR. (Do not readjust
reference supply.) Record dc null meter indication.
5-4
Section V
MHz. Dc null meter reading
I
. . . . . . . . . . .
. X I O
f. Set 652A FREQUENCY dial for 1 2 Hz and repeat
Step 5·12e.
g. Set 652A FREQUENCY dial for 1 5 Hz and repeat
Step 5·12e.
h. To determine that the readings taken in Steps 5·1 2e,
f, and g are within tolerance, two conditions must be met:
1 ) Each reading must be within 2% of the
reference level established in Step 5·12b. (See Table
5-3.)
2) The difference between the higbest and lowest
reading must be no greater than 2% of the reference
level established in Step 5·l2b.
These two conditions verify 652A output flatness, when
referenced to the normal monitor, of 2% between 1 0 Hz
and 20 Hz.
i. Repeat Steps 5·12b througb h (except, set up
reference at 20 Hz and use the frequencies and tolerances
listed in Table 5-4) to verify flatness of
range of 20 Hz to 4 MHz.
j. Repeat Steps 5·12b througb h (except, set up
reference level at 4 MHz and use the frequencies and
tolerances listed in Table 5-4) to verify flatness of 2% over
frequency range of 4 MHz to 10 MHz.
k. If tolerances are not met, first assure that tolerances
of Paragraph 5 · 1 1 are met, then perform Normal Monitor
Calibration of Paragraph 5-40.
(Amplitude readjusted to a reference on
5·13. Flatness.
expanded output monitor.)
a. Perform Step 5- 1 1 a (Note CAUTION).
b. Set 652A controls as follows:
FREQUENCY RANGE . . . . . . . . . . . . . .
FREQUENCY dial . . . . . . . . . . . . . . . . . . . . 2
OUTPUT ATTENUATOR . . . . . . . . . . 3.0 V
OUTPUT MONITOR . . . . . . . . . . . . NORMAL
OUTPUT AMPLITUDE and
VERNIER . . . . . . . . . Adjust for a monitor
c. Set OUTPUT MONITOR switch to EXPAND and
adjust REF SET and VERNIER controls for 0% indication
on the top (blue) scale of the 652A monitor.
d. Adjust reference supply for null indication on the dc
null meter.
e. Set 652A FREQUENCY dial to
f. Readjust 652A OUTPUT AMPLITUDE and VERN·
IER controls (if necessary) for 0% indication on 652A
I % over frequency
X I O
indication of 3.0 V.
I .
Model 652A