Orban OPTIMOD-FM 8700, Operating Manual

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OPERATION ORBAN MODEL 8700i
This control affects both the HD and FM processing chains regardless of the setting
of the
FM

HD C
ONTROL
C
OUPLING
control.
In most cases, we recommend that the phase rotator be left active. How-
ever, because it can slightly reduce the clarity and definition of program
material, you can defeat it if you are operating the 8700i conservatively
and not attempting to achieve very high on-air loudness.
You have somewhat more leeway than you do in older Orban FM proces-
sors like the 8200 because the 8700i’s new distortion control will work to
help prevent audible speech distortion even when the phase rotator is
switched out.
Multipath Mitigator / Phase Corrector See “Multipath Mitigator” Left/Right Phase
Skew Correction on page 3-8.
Subharmonic Injection The subharmonic synthesizer generates subharmonics of fun-
damental frequencies in the 50-90 Hz range. The subharmonics are one octave be-
low the frequencies from which they are generated (i.e., 25 to 45 Hz) and track the
levels of their generating frequencies. Subharmonic injection can be varied from 0
to 100% of the level of the generating frequency. 50% is a good starting point for
popular music formats.
If input program material below 50 Hz is present, the subharmonic synthesizer au-
tomatically reduces the level of the synthesized subharmonics to prevent excess
build-up of energy below 50 Hz (i.e. the amount of subharmonic injection will be
lower than the setting of the
S
UBHARMONIC
I
NJECTION
control).