Internal Phase Modulation Deviation Accuracy

This test compares the selected phase-modulation (ΦM) deviation to the measured ΦM deviation.

A measuring receiver is used to demodulate the ΦM signal and indicate the recovered phase deviation. In order to increase the accuracy of the measurement (i.e., lower the uncertainty), the ΦM signal is demodulated by the FM demodulator of the measuring receiver. The measured FM deviation is then divided by the FM/PM rate to obtain the PM deviation.

Required Test Equipment

Instrument	Critical Specifications for This Test	Recommended Model¹
Measuring Receiver	FM Deviation Accuracy	8902A

Refer to the main equipment list for alternate models.

Connections and Setup Procedures

All test equipment requires a 30 minute warm-up period to ensure accurate performance.
In the following test setup, direct cable and adapter connections are designated as solid lines. Changeable cable and adapter connections are designated as dashed lines.
Connect all test equipment as shown.
Connect GPIB cables to all GPIB-controlled test equipment.
While performing this test, follow all instructions on the controller display.

Measuring Receiver Calibration Setup

Phase Modulation Deviation Accuracy Test Setup