External FM Deviation Accuracy

FM deviation accuracyis checked for CW frequencies from 500 MHz to 1.0 GHz. If the DUT meets the accuracy specification in this frequency range, accuracy in all other frequency ranges will be assured.

A measuring receiver is used to demodulate the FM signal and indicate the recovered FM deviation. The measuring receiver is calibrated prior to the measurement.

Required Test Equipment

Instrument	Critical Specifications for This Test	Recommended Model¹
Spectrum Analyzer	FM Deviation Accuracy	E444xA² Opt 1DS, 123³
Function Generator	none	33250A
Digital Voltmeter	AC True-RMS Accuracy	3458A Opt 002

Refer to the main equipment list for alternate models.
Depending on your frequency range needs, choose either an E4440A, E4443A, E4445A, E4446A, or E4448A. (E4447A is for Power Level Accuracy adjustment only.)
Options 1DS and 123 are for ESGs > 3 GHz.

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

FM Deviation Accuracy Test Setup