Adjustment Procedures; Power Supply; Reference Oscillator; Vto Linearity - HP 3320A Operating And Service Manual

Model 3320A!B ADJUSTMENT PROCEDURES
Section V
5-27. ADJUSTMENT PROCEDURES.
5-28. The following is a complete adjustment procedure
for the 3320A/B. This procedure should be conducted only
if the 3320A/B has failed the performance tests. If proper
performance cannot be achieved by the adjustment proce-
dures, refer to the troubleshooting procedures, Section VII.
5-29. Power
Supply.
5-30. This adjustment procedure sets the
+
15 V de supply
and checks the voltages of the - 15 V dc, ± 5 V dc, and
± 30 V de supplies.
3.
Connect a de voltmeter between
AI?
pin
L
(+
15 V de) and AI7 pin 10 (ground).
b. Adjust AI7R23 (+ 15 V adjust) for 14.950 V de to
15.050 V de.
c. Connect the de voltmeter to the following pins and
insure each voltage is within the tolerances shown.
AI7pin 14 5.000t05.300
AI7 pin p 5.000 to 5.300
AI7 pin 7 ·4.850 to - 5.370
AI7pin8.......... . .. -14.8to-15.2
d. Connect the de voltmeter ground to A 17 pin 4.
Check the following voltages to insure they are within the
tolerances shown.
b. Connect the oscilloscope to A7TPl. Connect the rear
panel output of the counter to the EXT FREQ REF input
on the rear panel of the 3320A/B.
c. Set the counter rear panel MODE to I T STD FREQ
and OUTPUT STD FREQ to 10 MHz.
d. Adjust A8C4 (20 MHz ADJUST) until the display on
the oscilloscope is a sinewave
>
6 V p-p.
e. Ground the oscilloscope input and adjust trace for
center of display. Set oscilloscope input to de and readjust
A8C4 for 0 V de with no sinewave on oscilloscope display.
f. Connect the counter to the
I MHz OUT on the rear
panel of the 3320A/B. Counter indication should be I MHz
± I Hz.
5-33. VTO Linearity.
5·34. This adjustment procedure sets the VTO for a linear
output over the 3320A!B frequency range.
a. Connect the de voltmeter to A3TP2. Set the
3320A/B FREQUENCY to 12.99 and adjust A3R38
(PRETU E ADJUST) for a voltmeter indication of
- 10 V de ± 0.3 V de.
b. Connect the de voltmeter to A3TPI. Set the
3320A/B FREQUENCY from 00.99 to 12.99 in I MHz
steps. The de voltmeter indication should not be more
negative than - 4V de on each frequency setting.
AI7pinB
AI7pinC
. . . . . . . . . . . . . . 29.125 to 30.875
. . ·28.800 to . 31.200
5-35. Vernier.
5-31. Reference Oscillator.
5-32. This adjustment procedure sets the 20 MHz Refer-
ence Oscillator by monitoring the I MHz output on the rear
panel of the 3320A/B. It also sets the External Reference
Phase Lock circuitry.
NOTE
If Ihe 3320A/B being adjusted is an Option
002, steps band c of Ihis performance lest do
not need
to
be performed. If the 3320A/B
being adjusted is not an Option 002, step a of
this performance test does not need to be
performed.
a. Disconnect the short cable between the EXT FREQ
REF and the 5 MHz OUT on the 3320A/B rear panel.
Connect the electronic counter to the 5 MHz OUT and
adjust the COURSE and FINE adjustments on the 3320A/B
rear panel for 5,000,000 Hz. Reconnect the short cable
between the EXT FREQ REF and the 5 MHz OUT.
Connect the oscilloscope to A7TP I
5-36. This adjustment procedure sets the Vernier Oscillator
for a 10kHz swing (VTO output) on the front panel
Vernier.
a. Set the 3320A/B FREQUENCY TO 12.99, RANGE
to 10 MHz, VERN IN/VERN OUT to VERN IN.
b. Connect the de voltmeter to AITPI. Adjust AIRI
(DC REF ADJ) for a de voltmeter indication of· 6.06 V de
±
0.02 V de.
c. Connect the counter to the 3320A/B rear panel
L.a.
OUTPUT (20-33 MHz). Set the 3320A/B FREQUENCY to
0000, adjust Al R50 for 20 MHz ± 100 Hz.
d. Connect the oscilloscope to AITP2 through a 6.8 pF
capacitor. Adjust AIC3 (10 MHz LEVEL ADJUST) for
maximum signal on oscilloscope display. Display should be
>
250 mV pop.
e. Set the 3320A/B Vernier to 99. Adjust AIR34
(10 kHz ADJUST) for 20,010,000 Hz to 20,010,075 Hz
indication on the counter.
f. Set the 3320A/B Vernier to 50. Adjust AI R50
(5 kHz ADJUST) for 20,004,950 Hz to 20,005,050 Hz
indication on the counter.
5·11