Specifications

Phase Shifter: A Phase Shifter is required to achieve quadrature for the
FM Discriminator measurement when the source frequency cannot be
adjusted. Depending on the Quadrature Method selected, the HP 3048A
responds differently. For example, if you specify "Quadrature will be
established by adjusting the source frequency", you will have to adjust the
frequency of the source to obtain quadrature, (unless the source is under
System control). If "Quadrature will be established manually" is specified,
the HP 3048A expects you to acquire quadrature by adjusting the phase
shift of one path.
Cal Source: This block will appear on the Source Control display when
"Derive from Rate and Deviation" Calibration Process was selected. Either
a users Cal Source under Manual Control or a supported RF Source under
System Control can be selected for the Calibration Source. The Calibration
Source must have a calibrated FM output. Under Manual Control the
system will prompt you to connect the Cal Source and apply modulation
as well as disconnect it after the calculation process is complete.
Delay Line: The Delay Line is represented by _ J U U U U U
in the diagram. A Delay Line is required to decorrelate the Phase Noise
of the DUT. (FM Discriminator)
(Refer to Graph 5 Approximate Sensitivity of Delay Line Discriminator
Chapter 7 Quick Reference for details on required delay lines.)
Source Control: $N w/FM Discriminator 2-109