Check Distortion And Distortion Measurement Accuracy; Specification Checked; Option 40 Distortion Measurement Accuracy - Tektronix VM700T User Manual

Check Distortion and Distortion Measurement Accuracy

Specification Checked

Option 40 Distortion
Measurement Accuracy
VM700T Option 40/41/42 Audio Measurements User Manual
6. Set the sine-wave generator for each of the frequencies and amplitudes you
have selected to test.
7. At each frequency, check that the measured level is accurate to the limits
shown (record the level for each frequency).
8. Verify that any differences between the measured levels recorded for each
frequency are within the flatness specification given in Table B-2.
This procedure verifies that residual THD+N is 0.03% or less, and then checks
the THD+N accuracy of the audio option by reading a known signal.
THD+N accuracy is 10% of the reading 1 digit for harmonics at input levels
of –20 dBu or greater in a 33 Hz to 22 kHz bandwidth.
1. Check residual THD+N.
a. Apply a signal (between –20 dBu and +30 dBu in amplitude) from a
sine-wave generator to the VM700T Audio Option 40. See Figure B-2
for a cabling diagram. The generator should be set at 50 Ω output
resistance.
Figure B-2: Option 40 cable connections for distortion measurement accuracy
check
Appendix B: Verification Procedure
To Option 40 Audio
Input Connector
B-5