Agilent Technologies 8753ES Option 011 Service Manual page 329

Node 30 FN VCO Det (A14 VCO detector)
Perform step A14 and then press
Scale Ref 50 k/m
See whether the FN VCO is oscillating. The trace should resemble
Figure 10-17 Analog Bus Node 30
Node 31 Count Gate (analog bus counter gate)
Perform step A14 and then press
You should see a flat line at +5 V across the operating frequency range. The counter gate
activity occurs during bandswitches, and therefore is not visible on the analog bus. To view
the bandswitch activity, look at this node on an oscilloscope, using
in
AUX OUT on OFF
Chapter 10
ANALOG IN
Meas
.
Meas ANALOG IN
Table 10-12 on page
Service Key Menus and Error Messages
30 x1
31 x1
10-21.
Service Key Menus
RESOLUTION [HIGH]
Figure 10-17.
Scale Ref 2 x1
. Refer to
AUX OUT ON
10-39
.