HP 8340B Manual page 59

4-12. PULSE MODULATION RISE AND FALL TIME (Cont'd)
6. The 90% point of the envelope rise time should be less than 25 nanoseconds (5 horizontal divi-
sions) from the 10% point.
7. Adjust the oscilloscope horizontal position control to view the modulation envelope fall time.
Position the waveform so that the modulation envelope crosses the 90% graticule at a vertical
graticule line similar to Figure 4-15.
8. The 10% point should be <2S nanoseconds (S divisions) from the 90% point.
9. Repeat steps 5 through 8 at CW frequencies of 3, 9,15, and, if the DUT is an HP 8340B, 22 GHz.
Set the LO CW frequency to be 50 MHz below the DUT's frequency.
HP 8340B/41B
Figure 4-14. Pulse Modulation Rise Time Waveform
Figure 4-15. Pulse Modulation Fall Time Waveform
Performance Tests 4-61/4-62