HP 8562E, Service Manual

Page: 346 / 482

Narrow 10 resolution bandwidth:
Check for printed-circuit board contamination. Clean
the board required.
IF Gain Compression in 10 resolution bandwidth:
FET transistors Q202, Q501,
and Q503 can deteriorate with age. Measuring less than 0 volts on the FET source indicates a
bad FET.
1 0 d B
R L
B R O K E N B R O K E N
\\
\\
C E N T E R C E N T E R
* R B W * R B W V B W V B W
S P A N S P A N
S W P 7 0 m s S W P 7 0 m s
S K 1 8 4
Figure 9-15. Faulty Crystal Symmetry
Refer to function blocks B, H, and I of A5 IF filter schematic diagram (sheets 1 of 3 and
2
of
3)
in the
HP 8560 E-Series Spectrum Analyzer Component Level Information.
On the HP 85623 spectrum analyzer, press (PRESET), , and
Press and IF
3. Disconnect W29 (coax 7) from and W27 (coax 3) from
4. Inject a -5 10.7 MHz signal into
5. Monitor the output of with another spectrum analyzer.
6. Simultaneously decrease the signal generator output and HP 85623 spectrum analyzer
reference level in 10 steps down to a -50 reference level.
7. At each step, the signal displayed on the other spectrum analyzer should be close to
(More subtle IF gain problems might require smaller signal generator and
reference level steps.)
8. Reconnect W29 to and W27 (coax 3) to
IF Section 9-31