Orban OPTIMOD-FM 5500 Operation Manual page 67

OPTIMOD-FM DIGITAL
15. Set the composite output level.
[Skip this step if you will not be using the composite output(s).]
A) Observe the modulation produced by the 5500's C
modulation monitor or modulation analyzer. Turn the knob to make the
modulation monitor read 100% modulation (usually 75 kHz deviation).
If you are using program material, make sure that the program material is loud
enough to produce peaks of frequent recurrence that hit the 5500's peak limiting
system, thereby defining the maximum peak level that the 5500 will produce. In the
U.S., we recommend using 900s peak weighting on the peak modulation indicator,
as permitted by F.C.C. rules. This will cause the monitor to ignore very low energy
overshoots and will result in the highest peak modulation permitted by law.
In other countries, use a peak-indicating instrument as specified by the regulatory
authority in your country.
If you are required to obey the multiplex power limits specified by ITU-R BS412-9,
you may seldom see peaks hitting 75 kHz deviation. In this case, we advise you to
set the output level using the 5500's reference 100Hz tone.
B) Press the Next button and repeat for C
16. Set the digital output level.
A) Press the Next button.
B) [Skip this step if you are not using the digital output.]
Turn the knob to set the desired digital output level corresponding to
100% modulation, in units of dB below full-scale.
The most accurate way to set this control is by observing a modulation monitor or
analyzer connected to your transmitter.
17. Set the analog output level.
A) Press the Next button.
B) [Skip this step if you are not using the analog output.]
Turn the knob to set the desired analog output level corresponding to
100% modulation, in units of dBu (0 dBu = 0.775 Vrms).
The most accurate way to set this control is by observing a modulation monitor or
analyzer connected to your transmitter.
C) Press the Next button.
If you activated the modulation setup tone in step (14.A) on page 2-18,
the tone will turn off automatically.
D) Press the Next button.
OMPOSITE
O 2.
OMPOSITE UTPUT
INSTALLATION
O 1 on a
UTPUT
2-19