HP 5340A Operating And Service Manual page 107

Model 5340A
Maintenance and Service
10 MHz DOUBLER ADJUSTMENT (05340-60012)
4.
Remove the cover on the large casting by removing 12 screws. Locate A15 10 MHz Doubler Board (05340-
a.
60012). Do not remove board. Do not use a n extender board.
b. Set Dual Trace Oscilloscope for sensitivity of 0.05 V/cm with a sweep time of 0.1 psec/cm.
B
Set Channel polarity to
Using 1O:l divider probes, connect oscilloscope Channels A and
C.
scope display control to A plus
d. Adjust capacitor A15C3 for maximum amplitude of the signal on the oscilloscope.
e. Adjust A15C13 and A15Cll for maximum amplitude on the oscilloscope. Since these two adjustments
interact, repeat the procedure several times to achieve the optimum setting.
Switch Oscilloscope to A&B only. Verify that signals are of approximately the same amplitude.
f.
5. ADJUSTMENT OF A8 (05340-60006) AND A9 (05340-60007)
Remove A7 (05340-60005) board and install Feed-Forward Simulator K05-5340A in XA7. See Paragraph
a.
5-13 for description of K05-5340A.
b. Set KO5 switch to LOCK.
Using VTVM, measure feed-forward voltage
C.
on K05-5340A for a 9.00 volt reading.
d. Adjust A8R13 (LEVEL) and A9R4 (GAIN) fully clockwise.
e. Set controls on Oscilloscope to:
CHANNEL A to 0.02 V/cm; AC coupled;
TRIGGER to internal;
MODE to Norm
SWEEP to 50 ps/cm
DISPLAY to CHANNEL A
f. Using 1 O : l divider probe, connect Channel A of the oscilloscope to XAll(1)
Adjust Channel A position to center the sine wave on the screen.
h. If a large misadjustment exists, no sine wave will be displayed on Channel A. If necessary, adjust A9R1
(OFFSET) until a sine wave is displayed.
i. Using BNC to alligator clip adaptor, connect "VCO #1 to Counter" signal (available a t A16J6) to INPUT
BNC on the 5340A. Set RANGE switch to "10 Hz to 250 MHz". Display should be between 100 to
185 MHz. Vary the KO5 VOLTAGE CONTROL potentiometer s o that counter displays
frequencies from 100 to 185 MHz and note the point of maximum distortion of the scope display.
Adjust KO5 potentiometer for maximum distortion of the sine wave and the counter display within
the 100 to 185 MHz range.
Set the scope sweep to 5 ps/cm.
k. Back off A9R4 (GAIN) ccw just enough for minimum side jitter (phase noise) of the sine wave. It may be
helpful to set the scope sweep to 2 ys/cm and 1 ps/cm to observe parts of the wave.
1.
Connect a DVM to "TL Control" voltage, available a t XA9(15).
n. Vary VOLTAGE CONTROLon h 0 5 so counter display ranges from 100 to 185 MHz, and note the point
"TL Control" voltage is maximup. Record this voltage. Vmax
Find the point in the 100 -18dMHz range where "TL Control" voltage is minimum. Record this voltage.
n.
Vmin =
5-6
Figure 5-2. Adjustment Procedures (Continued)
up and A to up.
B.
(FF)
from XA7(10) to ground. Adjust VOLTAGE CONTROL
up
-
slope; AC
B
to XA15(1) and XA15(2). Switch oscillo-
(MIX SIG. 20
a
range of
=