Orban Optimod-TV 8382, Руководство по эксплуатации

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OPTIMOD-TV DIGITAL OPERATION
3-23
PH-ROTATE (“Phase Rotator”) is not a stereo enhancer control. It determines if the
phase rotator will be in-circuit. The purpose of the phase rotator is to make voice
waveforms more symmetrical. This can substantially reduce distortion when they are
peak limited by the 8382’s back end processing.
In most cases, we recommend that you leave the phase rotator active to minimize
speech distortion. However, because it can slightly reduce the clarity and definition
of program material, you can defeat it if you are operating the 8382 conservatively.
Stereo Enhancer Controls
The stereo enhancer emulates the Orban 222 analog stereo enhancer. The enhancer
has gating that operates under two conditions:

The two stereo channels are close to identical in magnitude and phase.
In this case, the enhancer assumes that the program material is actually
mono and suppresses enhancement to prevent the enhancement from
exaggerating the undesired channel imbalance.

The ratio of L–R / L+R of the enhanced signal tries to exceed the threshold set by
the L-R / L+R Ratio Limit control.
In this case, the enhancer prevents further enhancement in order to pre-
vent excess L–R energy, which can increase multipath distortion.
The stereo enhancer has the following controls. Note that “advanced” controls are
accessible only from 8382 PC Remote software.
Stereo Enhancer Controls
Basic / Full Modify Name Advanced Name Range
ENH AMT Stereo Enhancer Amount 0.0 ... 10.0
RATIO LMT L–R / L+R Ratio Limit 70 … 100%
Table 3-3: Stereo Enhancer Controls
ENH AMT sets the maximum spatial enhancement. When set to O
UT
, it bypasses the
stereo enhancer.
RATIO LMT (“L–R / L+R Ratio Limit”) sets the maximum amount of enhancement to
prevent multipath distortion. However, if the original program material exceeds this
limit with no enhancement, the enhancer will not reduce it.
AGC Controls
The AGC is common to the Two-Band and Five-Band structures.