Specifications

Description of the FM Rate and Deviation Spur
Calibration Method
The Calibration Source must have a calibrated FM output. The FM
accuracy of the calibration source must be within 10% to ensure the
required Discriminator Constant accuracy of less than 1 dB. (If the DUT
has a calibrated FM output it can be used as the calibration source.) In most
cases, the DUT will be replaced by a calibration source for determining
the Discriminator Constant. The calibration source output level must be
adjusted to within ±0.3 dB of the DUT's output level.
The FM Deviation must be less than j^ to maintain the small angle
criteria. A recommended frequency rate of less than -^ will ensure that
the calibration spur is within the linear region of the discriminator. (A rate
of greater than ^f is beyond the linear response region. A frequency of
greater than ^7 violates the Small Angle Criteria and will produce invalid
results.)
The FM Rate and Deviation method can be performed either manually or
with system control.
Manual control If the calibration source is not under system control,
you will be required to connect the calibration source, adjust it to the
appropriate settings (the parameters defined for the measurement), and
adjust its frequency to obtain quadrature when the Connect Diagram
appears. The Connect Diagram will appear again after the calibration
process is complete to provide connection information for the DUT. The
output level of the DUT must be within ±0.3 dB of the calibration source
level to ensure the validity of the Discriminator Constant.
Calibr Process; $N w/FM Discriminator 2-87