Agilent Technologies 8719ET Service Manual page 281

8719ET/20ET/22ET
8719ES/20ES/22ES
RF Network Analyzers
16.2nd LO (2nd converter reference)
Counter ON: analog bus
Reading: 9.996 MHz
This node counts the 2nd LO used by the 2nd converter assemblies to produce the 2nd
IF of 4 kHz.
17.PL Ref (Phase lock reference)
Counter ON: analog bus
Reading: 1 MHz
This node counts the reference signal used by the phase comparator circuit on the A11
phase lock assembly.
18.VCXO Tune (40 MHz VCXO tuning voltage)
This node displays the voltage used to fine tune the A12 reference VCXO to 40 MHz.
You should see a flat line at some voltage level (the actual voltage level varies between
instruments). Anything other than a flat line indicates that the VCXO is tuning to
different frequencies. Refer to the
19.A12 Gnd (Ground reference)
20.A12 Gnd (Ground reference)
Service Guide
"Frequency Accuracy Adjustment" on page
Service Key Menus and Error Messages
Analog Bus on OFF
3-41.
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