Distortion Test - HP 652A Operating And Service Manual

b. Set 652A controls as follows:
FREQUENCY RANGE . . .
FREQUENCY dial
. . . . . . • . . . • . . . . • . • . .
OUTPUT ATTENUATOR . . . . . . . . . . 3.0 V
OUTPUT MONITOR . . . . . . . . . . . . NORMAL
c. Set 355D attenuator switch to 90 dB position.
d. Set 461A amplifier gain switch to 40 d B position.
e . Turn the 652A AMPLITUDE and VERNIER controls
maximum clockwise. Select the range on the 3400A that
gives an indication of > 1 .0000 V de on the 34740A. Now
adjust the AMPLITUDE controls to give a 1 .0000 V de
reading on the 34740A.
NOTE
Do not readjust the 652A AMPLITUDE and VER­
NIER controls during this test.
f. Check 652A OUTPUT ATTENUATOR in each posi­
tion by decreasing attenuation on external attenuator as
attenuation is increased on 6S2A. Digital voltmeter indica­
tion should be:
±
1) 1 .0000 .0075 V de for 3 V through .3 mV
(+
ranges 20 dB 59 - 60 dB) verifying an overall
±
accuracy of .075 dB from
- 60 dBm.
±
2) 1 .0000 0.02 V de for 0 . 1 mV range (- 70 dB)
verifying an accuracy of ± 0.02 dB for the
. 70 dBm position.
g. Repeat Steps c through f of this paragraph with 652A
frequency set to 10 MHz.
h. If attenuation is out of tolerance, refer to Paragraph
5-57.
5-16. Amplitude Control Test.
a. Connect ac voltmeter to 50 ohm output terminal as
shown in Figure 5-2.
TEST OSCILLATOR
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5-6
Section V
. . . . . . . . . . X I K
.
1
20 dBm to
+
50 OHM
FEED THRU
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ADAPTER
F igure 5·5. D istortion Test.
b. Set 652A controls as follows:
FREQUENCY RANGE . . . . . . . . . . . . . Xl 00
FREQUENCY dial . . . . . . . . . . . . . . . . . . . . 4
OUTPUT ATTENUATOR .
OUTPUT MONITOR . . . . . . . . . . . . NORMAL
OUTPUT AMPLITUDE
and VERNIER . . . . . . . . Extreme Clockwise
c. Note reading on ac voltmeter.
d. Set OUTPUT AMPLITUDE and VERNIER controls
to extreme counterclockwise position. AC voltmeter should
read 20 dB or more below reading noted in Step c. This
verifies an amplitude control of at least 20 dB.
5-17. D istortion Test.
a. Connect distortion analyzer to 652A as shown in
Figure 5-5.
b. Set 652A controls as follows:
FREQUENCY RANGE . . . . . . . . . .
FREQUENCY dial . . . . . . . . . . . . . . . . . . . . 1
OUTPUT ATTENUATOR
OUTPUT MONITOR . . . . . . . . . . . . NORMAL
OUTPUT AMPLITUDE
and VERNIER
. • • . . . . . . . . . . . .
c. Distortion level, as indicated on distortion analyzer,
should be less than I %.
d. Repeat Steps b and c to check distortion at each of
fre quency settings shown in Table 5-5 (part A).
e, Disconnect 652A output from distortion analyzer
and connect to wave analyzer (remove 50 ohm feedthru
termination),
f.
Check distortion at each of frequency settings shown
in Table 5-5 (part B). Use the following formula to
compute distortion.
DISTORTION ANALYZER
- - - -
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3.0 V
. • . . . • . . .
.
. X I K
. .
3.0 V
. . . . . . • . • .
Adjust for
monitor indication
of 3.0 V.
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Model 652A