Motorola ASTRO APX MOBILE O2 CONTROL HEAD, User Manual

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Advanced Features
English
82
Hear Clear
There are two components of Hear Clear.
1
Companding:
Reduces the channel noise, e.g. OTA transmission, that is
predominantly present in UHF2 and 900 MHz channel with
the following features.
•
Compressor – reduces the background noise flow and the
speech signal at transmitting radio.
•
Expander – expands the speech while the noise flow
remains the same at receiving radio.
2
Random FM Noise Canceller (Flutter Fighter):
Reduces the unwanted effects of random FM noise pulses
caused by channel fading under high Signal-to-Noise (S/N)
conditions such as in a moving in a transportation. The fading
effects, heard as audio pops and clicks, are cancelled without
affecting the desired audio signal.
The Random FM Noise Canceller operates only in receive
mode.
Note: This feature must be preprogrammed by a qualified
radio technician. Check with your dealer or system
administrator for more information.
The Global Positioning System (GPS)
This feature uses information from the Global Positioning
System (GPS) satellites orbiting the Earth to determine the
approximate geographical location of your radio, expressed as
latitude and longitude. The availability and accuracy of this
location information (and the amount of time that it takes to
calculate it) varies depending on the environment in which you
are using the GPS feature.
For example, GPS location fixes are very difficult to obtain
indoors, in covered locations, between high buildings, or in
situations where you have not established a clear broad view of
the sky.
Understanding the GPS Feature
The GPS technology uses radio signals from earth orbiting
satellites, to establish the location co-ordinates, maximizing
your view of clear unobstructed sky is essential for optimum
performance.
Where adequate signals from multiple satellites are not
available (usually because you cannot establish a view of a
wide area of the sky), the GPS feature of your radio will not
work. Such situations include but are not limited to:
• In underground locations
• Inside of buildings, trains, or other covered vehicles