HP 8562E, Service Manual

Page: 344 / 482

Check the crystal shorting switches as follows:
1. On the HP 85623 spectrum analyzer, press and set the controls as follows:
Resolution bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 MHz
Span . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500kHz
Center frequency
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...300 MHz
2. On the HP 85623 spectrum analyzer, connect the 300 MHz CAL OUTPUT to the INPUT
3.
If the trace flatness is not within 2.5 a failure probably exists.
4. A trace similar to Figure 9-13 indicates a crystal short failure.
5. Press (SPAN to set the spectrum analyzer to 3 MHz. A trace that slopes across the screen
(see Figure 9-14) indicates a failed LC pole. To isoiate the broken pole refer to the shape
factor information in “30 Resolution Bandwidth Problems.”
1 0 d B
R L
C E N T E R
S P A N
V B W S W P 5 0 m s
S K 1 8 2
Figure 9-13. Faulty Crystal Short
IF Section 9-29