Orban OPTIMOD-FM 8600Si, Operating Manual

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OPTIMOD-FM DIGITAL INSTALLATION
2-17
7. Set external AGC mode.
Most of the 8600Si’s processing structures control level with a preliminary AGC
(Automatic Gain Control). If you are using a suitable Automatic Gain Control at
the studio (such as an Orban 8200ST OPTIMOD-Studio or 464A Co-Operator), the
AGC in the 8600Si should be defeated. This is so that the two AGCs do not
“fight” each other, and so they do not simultaneously increase gain, resulting in
increased noise.
A) Press the Next
button.
B) Set external AGC mode by turning the knob.
•
Set the field to
Y
ES if you have a external AGC (such as an Orban 6300,
1100V2, 1101, Orban 8200ST OPTIMOD-Studio, Orban 464A Co-Operator, or
similar AGC) installed at your studio feeding the studio-to-transmitter link.
This setting appropriately defeats the 8600Si’s AGC for all presets.
•
Set the field to
N
O
if you do not have a external AGC installed; this setting
enables the 8600Si AGC status to be determined by the selected preset.
•
If you are using an Orban 4000 Transmission Limiter, set field to
N
O
(so that
the AGC function in the 8600Si continues to work). The Orban 4000 is a
transmission system overload protection device; it is normally operated be-
low threshold. It is not designed to perform an AGC or gain-riding function,
and it cannot substitute for the AGC function in the 8600Si.
8. Select your primary input (analog or digital).
A) Press the
Next
button.
B) If your main input source is digital, turn the knob to select
D
IGITAL or
D
IGITAL
+J17
. Otherwise, select
A
NALOG .
D
IGITAL
, not
D
IGITAL
+J17,
is appropriate for almost anyone using the digi-
tal input . The only digital encoding that typically uses J.17 pre-emphasis
(of which we are aware) is NICAM.
9. Set operating levels.
You will set the operating levels of the 8600Si to match the input levels it is re-
ceiving so the 8600Si’s AGC can operate in the range for which it was designed.
There are separate settings for the analog and digital inputs. If you provide both
analog and digital inputs to the 8600Si, optimum adjustment is achieved when
the gain reduction meters show the same amount of processing for both analog
and digital inputs.
This will allow you to switch between analog and digital inputs without sudden
level changes.
A) Press the
Next
button.
B) Feed normal program material to the 8600Si.