Tait T805, Service Manual, Page: 26 / 96

5.4 Quasi-Synchronous Operation With ADNs
M805-00
30/09/96 Copyright TEL
which feeds into its LEM changes state (from logic 0 to logic 1), allowing independent
audio to be fed into the LEM. Note that, in order to key the inversion process for the
AIMs, either the AIMs' ICCS input must be active or the 2970Hz key tone must be
present in the audio.
Training is controlled by the System Controller. In training mode, the training signal is
split into two bands: 300Hz to 3kHz (HF training audio) and 45-300Hz (LF training
audio). The HF training audio is passed into the ADC-1 system along the same path as
normal speech audio, while the LF training audio follows the same path as the CTCSS
signal. They are summed in the LEM as for normal operation and then passed out to
the transmitter for the training process. Training is carried out using the same process
as described in Section 2.
Beyond the LEM the organisation of the Quasi-Synchronous System is independent of
the network type being used. The organisation of that part of the system is described in
Section 2.