Agilent Technologies 8719ET Service Manual page 112

Adjustments and Correction Constants
Reference Assembly VCO Tune Adjustment
Figure 3-7 VCO Tune Adjustment Location
5. Adjust VCO TUNE with a non-metallic adjustment tool to 0.0 V ±500 mV (within one
division of the reference line).
The adjustment is sensitive, and if out of adjustment may display an irregular
waveform. If so, slowly tune through the entire adjustment range to obtain a flat trace,
then carefully tune for 0.0 V. Once the adjustment is done, it should be rechecked with
the reference board reinstalled in the instrument, and at operating temperature.
In Case of Difficulty
If VCO TUNE cannot be adjusted as specified, and the instrument passes the Analog Bus
Correction Constants (Test 44) adjustment, the Reference (A12) assembly must be replaced
or contact the nearest Agilent Technologies sales or service office.
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8719ET/20ET/22ET
8719ES/20ES/22ES
RF Network Analyzers
Service Guide