Orban OPTIMOD-FM 8600, Operating Manual

Page: 75 / 397

OPTIMOD-FM DIGITAL INSTALLATION
2-15
•
HD
METERS
display the gain reduction of the left and right look-ahead lim-
iters that feed the HD outputs.
•
The
L
OUDNESS
L
EVEL
meters, which uses the ITU-R BS.1770-3 algorithm, in-
dicates the relative loudness level at the output of the digital and analog
radio processing chains. The reference level for the analog and digital pro-
cessing chains are set independently. The loudness level for the analog ra-
dio chain is shown as a number at the bottom of the main meter screen on
the 8600 unit; it is shown as a meter on PC Remote. See
BS.1770 Loudness
Level on page 1-24.
•
The
L
OUDNESS
GR
meters indicate the amount of gain reduction produced
by the BS.1770 Safety Limiters in the digital and analog radio processing
chains.
•
M
ULTIPLEX
P
OWER
GR / BS.1770 GR
METER
uses a two-color display to indi-
cate the action of the ITU Multiplex Power controller and the BS.1770 safe-
ty limiter in the analog radio processing chain. It shows how much the Mul-
tiplex Power Controller and BS.1770 Safety Limiter have reduced the clip-
per drive, reducing the average power in the processed audio. The BS.1770
gain reduction is shown in cyan and the multiplex power gain reduction is
shown in dark blue.
This meter, labeled “PWR,” is displayed on the 8600’s color LCD. It always
appears when the Two-Band Structure is active. When the Five-Band
Structure is active, the meter only appears when the Multiplex Power
Controller is turned on.
External AGC Installation (optional)
[Skip this section if you are not using an external AGC ahead of the 8600. Continue
with “Quick Setup” below.]
•
As of this writing, the currently manufactured Orban products that can be used
as external AGCs are Optimod-PC 1101/1101e and Optimod 6300. Their manuals
contain instructions on how to use them in this application. They are the pre-
ferred choices because their AGCs are identical to the AGC in the 8600.
•
Discontinued Orban products usable as external AGCs include the 8200ST, 464A
“Co-Operator,” 8100AST, and Optimod-PC1100. In this manual, we do not pro-
vide step-by-step instructions for setting up all of these older products, although
it should be easy to extrapolate from the instructions we provide for the 8200ST
below.
•
If you are using an Orban 8100AST (or 8100A/ST) external AGC, refer to page 1-
19.