HP 8591C User Manual page 74

Depth of video
1. Select a channel, then press
modulation test
2. The result is displayed at the bottom of the screen. This result is updated
every 10 analyzer sweeps (approximately every 3 seconds) and continues
until STOP MEAS or MAIN MENU is pressed. See Figure 2-20.
Large amounts of hum and low frequency disturbances may affect the measurement result. If so, use
TV line.
This test must have a white level present during the vertical interval because program video may not
always have white level available.
Making Channel Measurements
Main 1 of 3 DEPTH MOD .
Channel Measurements
I
2-31