AOR AR-ALPHA, Operating Manual

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9
Terminology
Search & Scan
If you have not used a wide band receiver before or you are not familiar with the terminology used, it is
very important to understand the difference between
SEARCH and SCAN modes.
SEARCH : The AR-ALPHA provides several operations where transmissions (active frequencies)
may be automatically located by sweeping the receiver over a wide frequency range, either from
the currently displayed frequency traveling upwards (or downwards) in a specified tuning
increment (step) or by sweeping over-and-over between two specified frequency limits. This
process is known as
SEARCHING , as the title implies, it can take a long time to find
transmissions due to their ‘often intermittent’ and brief nature. For this reason it is best to slice
large frequency ranges into smaller, more manageable pieces where they may be intensely
searched.
When examining large frequency segments, it is common to find that the majority of frequencies
are inactive at the time of the search and only a small number of the remaining constitute what
you really want. Searching still remains the best way to initially locate active and interesting
transmissions (in conjunction with a good list of active frequencies and a band plan).
SCAN : Once active transmissions have been identified (either by searching or by using a good
frequency guide), it is more efficient to store the data into memories which can be rapidly and
automatically monitored in succession, stopping when activity is encountered. This is a much
more efficient means of monitoring the most wanted frequencies you have targeted, that is, what
you most want to hear. By contrast, searching is very inefficient for day-to-day monitoring.
Note : It is very important that the squelch is advanced to cancel background noise for the
search & scan functions to operate properly. This is because the AR-ALPHA believes that
it has found an active frequency when the squelch opens and the “BUSY” lamp lights up.
Advance the squelch control clockwise until the background noise is just cancelled, this
is known as the “threshold” position. If the squelch control is advanced too far, weaker
signals may be missed.