Orban OPTIMOD-FM 8600Si, Operating Manual

Page: 53 / 356

OPTIMOD-FM DIGITAL INTRODUCTION
1-27
Low-Delay Monitoring
The 8600Si’s analog outputs can be switched to provide a low-delay monitoring
feed (see step (B) on page 2-31). This feed has no peak limiting and thus cannot
drive a transmitter, but its 3 to 8 ms delay is likely to be more comfortable to talent
than the 18 ms delay of the full processing chain because of less bone conduction
comb filtering.
If the talent relies principally on headphones to determine whether the station is on
the air, simple loss-of-carrier and loss-of-audio alarms should be added to the sys-
tem. The 8600Si can be interfaced to such alarms through any of its eight its GPI re-
mote control inputs, cutting off the low-delay audio to the talent’s phones when an
audio or carrier failure occurs.
The front panel headphone jack provides output matching the Analog Output, ex-
cept that it is always de-emphasized (even if the Analog Output is set with pre-
emphasis).
EAS Test
For stations participating in the Emergency Alert System (EAS) in the United States,
broadcast of EAS tones and data can be accomplished in three different ways:
1. Run EAS tones and data through the 8600Si.
Note that 8600Si processing may not allow the full modulation level as required
by EAS standards. It may therefore be necessary to temporarily defeat the
8600Si’s processing during the broadcast of EAS tones and data. Placing the
8600Si in its
BYPASS
Test Mode can defeat the processing. The
BYPASS GAIN
control allows a fixed gain trim through the 8600Si. See “Test Modes,” on page
3-85 for more information.
2. Place the 8600Si in Bypass mode locally.
A) Navigate to
Setup
> M
ODE
and set
M
ODE
to
B
YPASS
.
You can set the bypass gain with the
B
YPASS
G
AIN
control located to the
right of the
M
ODE
control.
B) Begin EAS broadcast.
After the EAS broadcast, resume normal processing:
C) Set the
M
ODE
to
O
PERATE
.
This will restore the processing preset in use prior to the Test Mode.