Orban OPTIMOD-AM 9300 Operating Manual Download

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OPERATION

ORBAN MODEL 9300

format requiring long-term listening to achieve market share, great care should be
taken not to alienate women by excessive stridency, harshness, or distortion.

AM radio has been losing its market share to FM in many countries because the pub-
lic perceives that AM has lower sound quality. While this is inevitably true (except in
the automobile, where multipath often degrades FM reception below “entertain-
ment quality”), the damage can be minimized by processing the audio to make the
best of the limitations of the AM channel and to avoid processing artifacts.
OPTIMOD-AM is uniquely effective in optimizing these trade-offs, and the discussion
below tells you in more detail how to do this.

Shortwave/HF Processing

The goals for HF broadcasters are likely to be quite different than they would be in
MW, LW, or FM broadcast. Listeners to HF broadcasts are often highly motivated and
will continue to listen even when the signal is severely degraded by poor propaga-
tion conditions or by interference that would almost certainly cause the average LW,
MW, or FM listener to tune to another station.

In LW and MW, the audio processor set-up controls are usually used to match the
processor’s ”sound” to a certain type of music or talk programming. HF is different.
In HF, the audio processor is usually adjusted to provide a sound at the receiver that
is as esthetically satisfying as possible,

given the probable signal quality at the re-

ceiver

. The broadcasting organization usually does not have the luxury of making

fine adjustments to match different types of program material, because such fine
adjustments will almost certainly be masked by the variability of the propagation
and interference experienced by the listener. This fact considerably simplifies the ad-
justment procedure.

We have tuned the 9300’s “HF” presets with these compromises in mind. There is a
general-purpose preset and a preset tuned to optimize voice intelligibility. We be-
lieve that further subtleties are inappropriate for the medium.

Working Together

Best results will be achieved if Engineering, Programming, and Management go out
of their way to

communicate

and

cooperate

with each other. It is important that

Engineering understands well the sound that Programming desires, and that Man-
agement fully understands the trade-offs involved in optimizing certain parameters
(such as loudness and coverage) at the cost of others (such as brightness or distor-
tion).

Fundamental Requirements:
High-Quality Source Material and Accurate Monitoring

Very clean audio can be processed harder without producing objectionable distor-
tion. If the source material is even slightly distorted, OPTIMOD-AM can greatly ex-
aggerate this distortion, particularly if a large amount of gain reduction is used. Po-
tential causes for distortion are poor-quality source material, including the effects of
the station's playback machines, electronics, and studio-transmitter link, as well as
excessive clipping settings in the OPTIMOD-AM processing. See

Maintaining

Audio