1-16
INTRODUCTION
ORBAN MODEL 9300
OPTIMOD-AM was designed with the assumption that one audio processor would
be devoted to no more than two transmitters, usually called main and standby (or
main and alternate). Each transmitter might be required to change power at night
or to drive a different antenna array. Only one transmitter is assumed to be on the
air at a given time.
To drive two transmitters, OPTIMOD-AM provides two mono analog outputs (called
Analog Output 1 and Analog Output 2) and one AES3 digital output, which can al-
ternatively be used to drive the main transmitter if it has a digital input.
OPTIMOD-AM provides four system presets for its transmitter equalizer controls and
certain other controls. Only one preset can be active at a given time; all three out-
puts receive the same transmitter equalization. This is consistent with the principle
that only one transmitter will be on the air.
Transmitter equalizer controls in a given system preset include:
LF Gain for the LF tilt equalizer [
LF
GAIN
]
LF Breakpoint Frequency for the LF tilt equalizer [
LF
FREQ
]
HF Shelf tuning [
HF
FREQ
]
HF Delay equalization [
HF
DELAY
]
System presets also contain the following controls:
System Lowpass Filter Cutoff Frequency [
LOW
PASS
]
System Lowpass Filter Cutoff Shape [
LPF
SHAPE]
System Highpass Filter Cutoff Frequency [
HIGH
PASS
]
Positive Peak Threshold (Asymmetry) [
POS
PEAK
]
For convenience and to describe their most common application, the four transmit-
ter equalizer presets are labeled TX1/DAY, TX1/NIGHT, TX2/DAY, and TX2/NIGHT, al-
though they can be applied in a completely general way to the requirements of
your transmission facility.
For example, in countries observing NRSC standards you might want to transmit the
full 9.5 kHz bandwidth during the day, and, in cooperation with other stations on
first-adjacent channels, reduce audio bandwidth to 5 kHz at night. This will elimi-
nate any skywave-induced monkey-chatter interference between first-adjacent
channels. Alternatively, your nighttime directional antenna array might have poor
VSWR performance at high modulating frequencies, so you might find that your
transmitter works better and produces less distortion if you limit the audio band-
width to those frequencies where the antenna is well behaved. Further, if you oper-
ate a talk format during certain parts of the day, you will probably find that you can
operate the processing for a louder on-air sound if you restrict the transmitted
bandwidth below the maximum permitted by government regulation. (Bear in mind
that most AM radios have an audio bandwidth of 2.5 to 3 kHz and changing trans-
Summary of Contents for OPTIMOD-AM 9300
Page 1: ...Operating Manual OPTIMOD AM 9300 Digital Audio Processor Version 2 0 Software...
Page 7: ...Operating Manual OPTIMOD AM 9300 Digital Audio Processor Version 2 0 Software...
Page 178: ...3 46 OPERATION ORBAN MODEL 9300...
Page 200: ......
Page 221: ...OPTIMOD AM DIGITAL TECHNICAL DATA 6 21...
Page 222: ...6 22 TECHNICAL DATA ORBAN MODEL 9300 CONTROL BOARD PARTS LOCATOR...
Page 228: ...6 28 TECHNICAL DATA ORBAN MODEL 9300...
Page 229: ...OPTIMOD AM DIGITAL TECHNICAL DATA 6 29 I O DSP BOARD LEFT AND RIGHT ANALOG INPUTS...
Page 230: ...6 30 TECHNICAL DATA ORBAN MODEL 9300 I O DSP BOARD ANALOG OUTPUTS...
Page 231: ...OPTIMOD AM DIGITAL TECHNICAL DATA 6 31...
Page 238: ...6 38 TECHNICAL DATA ORBAN MODEL 9300 FRONT VIEW REAR VIEW FRONT PANEL PARTS LOCATOR DIAGRAM...