Tektronix 070-8811-08 - Manual (Page 37)

Operating Basics
22 764 Digital Audio Monitor User Manual
Please be aware that although the peak indicators may reveal
higher peaks than VU or PPM ballistics, the indicators do act on
the same, processed data as the meters. If interpolation is ON, the
peak indicators show peaks in the oversampled data, and these
peaks may be higher than those in the raw input data (see
“Interpolation,” on page 50). If de-emphasis (AUTO, CCITT
J.17, or 50/15) is selected, the peaks — particularly at higher
frequencies — may be lower than in the raw data (refer to The
De-emphasis Submenu on page 53).
(9) Clipping flag. The clipping flag appears when the 764 detects clip-
ping and persists for the same hold time as chosen for the Mute
indicator. The user can specify the number of consecutive full
scale samples that constitute clipping. The range is from 1 to 100
samples. Like the Mute indicator, the clipping flag always reacts
to unprocessed input data, regardless of Interpolation or de-em-
phasis settings.
Configuring the Level Meters
You can configure the level meter scale with front-panel controls.
Other meter characteristics—such as ballistics, scale units, and
program/test levels—are configured through the on-screen Level
Meter submenu.
Variable scale. To adjust either the range or offset of the level meters,
press METER SCALE:EXPAND or METER SCALE:OFFSET,
then turn the multi-function knob. For best results (and least
confusion), expand the scale to the desired range first, then adjust the
offset to view the meter region of interest. For example, to change
normal scale to a custom scale showing only the –10 to –30 dBFS
range (see Figure 17):
1. Press METER SCALE:EXPAND, then turn the multi-function
knob clockwise [ ] to expand the scale range to 20 dB, top to
bottom.
2. Press METER SCALE:OFFSET, and turn the multi-function
knob counterclockwise [ ] to shift the scale upwards by
10 dB.