Orban OPTIMOD-FM 5500 Operation Manual page 79

OPTIMOD-FM DIGITAL
A) Navigate to Setup > I/O C
B) Repeat steps 1 through 4 (starting on page 2-28), but use the DI R
PPM) and R CH BAL controls for the digital section.
6. Defeat final clipper (optional).
If you are using the 5500 to drive a network with protection audio processors
(like Orban's Optimod-FM 2300) at each transmitter, you may wish to defeat the
5500's final clipper to prevent double clipping, which will unnecessarily increase
distortion on-air. To do this:
A) Navigate to the Setup > F
press the Next button until it does.
In PC Remote, this control is located in I/O > U
B) Set F
C
INAL LIP
This will also defeat the overshoot compensator.
Note that defeating the final clipper and overshoot compensator will in-
crease peak output levels, possibly to the point where the 5500's output
amplifier and/or digital output clips. It is wise to customize any presets
you are using by reducing the F
controls to their minimum values. This will greatly reduce the probability
of inadvertently clipping the 5500's output.
Unless defeated, the 5500's composite limiter will continue to control the
composite output level. However, you should not use the composite out-
put when the 5500's final clipper is defeated because this will remove the
advantages of the distortion cancellation in the 5500's final clipper. (The
composite limiter does not cancel distortion.)
7. Configure Composite Outputs
A) Navigate to Setup > S
to 50µs or 75µs, depending on your country's standard.
B) Set PILOT LVL to 9%.
If you have to reduce the setting of the composite level (C
C 2 LV) control to accommodate overshoots in the transmission path
OMP
following the 5500 (including the transmitter), you may have to increase
the setting of the
C) If your country enforces the ITU-412 multiplex power standard, set ITU412 to
. See step 20 on page 2-21.
O
N
D) If you are using the 5500's pilot reference output to drive a subcarrier genera-
tor, set the 19
erence and the 5500's pilot tone required by your subcarrier generator. In
most cases, this will be 0 degrees.
E) Press the Next button. If you need to apply the 5500's diversity delay to the
composite outputs, set D
> D I
ALIB IG
C
INAL LIP
to D .
D
EFEAT EFEAT
E
TEREO NCODER
P L
so that the pilot is still at 9% modulation.
ILOT EVEL
control to the phase relationship between the 19 kHz ref-
R
K EF
D to I
VRSTY LY
C > I and set the input to Digital.
N ALIB NPUT
. If F does not appear, repeatedly
C
INAL LIP
.
TILITIES
and O
C D
INAL LIP RIVE SHOOT
> Next > P -E . Set the pre-emphasis
RE MPH
. Otherwise, set it to O
N
INSTALLATION
(VU OR
EF
C D
OMP RIVE
1 LV or
OMP
.
UT
2-31