Orban Optimod-AM 9400, Operating Manual

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OPTIMOD-AM DIGITAL OPERATION
3-21
to trade off loudness against processing artifacts and side effects. Once
you have used
L
ESS
-M
ORE
, save your edited preset as a User Preset.
It is important to understand that each AM analog Factory Preset is actually a pair of
presets (each with
L
ESS
-M
ORE
capability), one optimized for narrowband operation
and one for wideband operation. The “wideband” parameters were tuned for NRSC
bandwidth and the “narrowband” presets were tuned for 5.0 kHz bandwidth. If you
have a Factory Preset on-air, the 9400 automatically switches to that preset’s “nar-
rowband” parameters if active Transmission Preset’s LOWPASS parameter is 7.0 kHz
or below. 7.5 kHz and above invokes “wideband.”
This automatic switching does not work with User Presets and Factory Presets that
have been modified but not yet saved as User Presets. If you routinely use User Pre-
sets on-air and switch bandwidths, and if you want the User Preset to change when
you change bandwidth, you must create two User Presets and recall the appropriate
preset at the same time that you change bandwidth.
If you want to create a User Preset by editing the AM analog processing with L
ESS
-
M
ORE
, be sure that the active Transmission Preset has the desired bandwidth before
you start. This will ensure that L
ESS
-M
ORE
calls up the correct parameters for your
desired bandwidth.
The one exception to the “wideband/narrowband” switching is the HF (shortwave)
presets. All HF presets are “narrowband.” The lowpass filter cutoff frequency is set
to 4.5 kHz in the preset itself and this will override the
LOWPASS
setting in the ac-
tive Transmission Preset.
HD Factory Presets are the same regardless of bandwidth because it is unnecessary
to change the tuning of a preset if the audio bandwidth is between 10 and 20 kHz,
which is the range typically found in digital radio channels.
Description of the Analog AM Factory Presets
Presets with “HF” in their names are narrowband presets intended for international
shortwave transmission where 4.5 kHz audio bandwidth and difficult propagation
conditions are the norm. All other presets are intended for MW or LW transmission.
All factory presets contain parameters for both the analog AM and digital radio
processing chains.
GEN MED is the default factory preset. It is based on the Medium-Fast multiband
release time and is adjusted to sound equally good on voice and music. It is most
appropriate for listeners in strong signal areas because it does not bring up low-level
material as much as presets based on the Fast multiband release time.
GEN HEAVY is based on the Fast multiband release time, and is designed to sound
good on voice and music. Because it processes harder than the
G
ENERAL
P
URPOSE
M
EDIUM
preset, it can be louder, but it does not sound as punchy or dynamic. It is a
good choice when many listeners are subject to noise and interference and you want
the highest possible loudness.