Keysight FieldFox Handheld Analyzers Service Guide           83
Theory of Operation
User Calibration in CAT, NA, and VVM Modes
User Calibration in CAT, NA, and VVM Modes
There are three types of calibrations for the CAT, NA and VVM modes: 
CalReady, QuickCal and Mechanical Cal. See the FieldFox Analyzer User's 
Guide (Part Number N9927-90001) "Calibration for CAT, NA and VVM Modes" 
section for specific instructions for performing these calibrations. Because NA, 
CAT, and VVM modes are very similar, a calibration that is performed in one 
mode can also be applied in the other modes.
When a user calibration is performed, the full frequency range of the analyzer 
is calibrated even though the current state of the analyzer may be less than the 
full range. This allows a calibration to be "interpolated" beyond the frequencies 
set at the time of calibration (an asterisk "*" on the display indicates 
interpolation).
Do not leave cal standards connected to the PORT 2 or PORT 1 ports for more 
than three minutes. Heat in the port connectors may affect the accuracy of the 
standards.
Factory Calibration (CalReady)
When the analyzer is adjusted at the factory or during annual calibration, a 
preset calibration is stored in the analyzer (CalReady).
The preset calibration covers the full frequency range of the analyzer. The 
preset calibration is active whenever “CalRdy” is displayed on the left side of 
the screen. Presetting the analyzer activates the preset calibration.
The preset calibration provides very good measurement performance at the 
PORT 1 and Port 2 connectors when the analyzer has thermally stabilized at 
room temperature. 
The preset calibration should be re-characterized every 12 months to maintain 
accuracy. This is accomplished via the Error Terms adjustment in the TME. 
Refer to Chapter 3.