Multitone FLA 872, Technical Manual

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TLA 852/FLA 872
TM1205 Issue 2 Page 3 - 3
The RF signal enters the aerial and is fed to the dual conversion superheterodyne
receiver. The signal is demodulated from RF to audio frequency digital form and is
then fed to the decoder. This results in the received data activating the memory,
display and the selected audible alert or vibrate alert.
To prolong the life of the battery, the receiver operates in battery economy mode.
When the unit is in standby mode, the receiver is powered up at regular intervals
(equivalent to once per batch) to allow the POCSAG decoder to search for
pre-amble. While the unit is receiving preamble on its allocated channel, the
receiver remains powered up. This allows the POCSAG decoder to search for a
SYNC word. When the SYNC word is found, ‘batch lock’ is achieved. In batch lock
the receiver is only powered up during the allocated frame to allow the POCSAG
decoder to search for its address. If the address is found, the receiver stays ON for
the duration of the message.