Orban OPTIMOD 6300 Operating Manual page 166

3-24
OPERATION
To produce look-ahead limiter gain reduction, turn up the L
step of the L -M
ESS ORE
1 dB and increases the input/output gain by 1 dB for signals below the limiter
-M
threshold. At L
ESS ORE
9 dB.
Instead of adjusting L
what L -M actually does). Do not set the F
ESS ORE
with this preset; doing so will compromise system headroom.
Adjusting the L
multaneously decreasing the threshold and increasing the make-up gain
in a protection limiter having threshold and output make-up gain con-
trols.
AGC+[FLAT, 50 s, 75 s] LIMITER: These presets allow the 6300 to serve as a stu-
dio AGC, substituting for the AGC in an Optimod at a radio or television transmitter
and providing protection limiting for the STL that links the output of the 6300 to
the input of the Optimod at the transmitter.
Choose the preset that matches the 6300's preemphasis setting (see step 9 on page
2-23). This step explains how to choose the 6300's preemphasis setting to match your
STL.
The 50  and 75 
presets have been tuned so that the 5-band compressor serves
S S
only as a subtle high frequency limiter that uses bands 4 and 5 to perform a few dB
of fast gain reduction with program material having strong high frequency content.
Band 5 operates without stereo coupling. This way, HF limiting triggered by high
frequency energy in one audio channel will not modulate high frequencies in the
opposite channel.
The F
preset is tuned so that it does not normally trigger gain reduction in the
LAT
6300's 5-band compressor — the Optimod at the transmitter should be the processor
that performs this multiband compression.
All AGC presets use the look-ahead limiter to prevent overloading the STL on peaks.
, the 50 
Compared to F
LAT
the look-ahead limiter to prevent strong high frequency energy from triggering au-
dible gain pumping or ducking. The high frequency limiting action in the 5-band
FACTORY PROGRAMMING PRESETS (PROTECTION; AGC)
Preset Names
AGC+50us LIMITER
AGC+75us LIMITER
AGC+FLAT LIMITER
LOOK-AHEAD LIMITER
PROTECT
SOFT KNEE 2B
control increases the drive level to the look-ahead limiter by
= 10, the processor's gain below threshold has increased to
-M , you can adjust the F
ESS ORE
-M or F L
ESS ORE INAL
and 75 
presets progressively reduce the drive level to
S S
Source Preset
AGC+50us LIMITER
AGC+75us LIMITER
AGC+FLAT LIMITER
LOOK-AHEAD LIMITER
PROTECT
SOFT KNEE 2B
Table 3-1: Protection and AGC Presets
-M
ESS
L D
INAL IMIT RIVE
L D
INAL IMIT RIVE control below "0"
D
controls is equivalent to si-
IMIT RIVE
Normal Less-More
5.0
5.0
5.0
1.0
1.0
5.0
ORBAN MODEL 6300
ORE control. Each
control (which