Figure 19: Representation Of The Waveform As Measured At Tp2 - Codan NGT 2010 RF Technical & Service Manual

NGT—Technical description (2010)
Time division multiplex audio channels
Drawing 04-03201, or
ALTERNATIVE TEXT
Drawing
The system audio uses TDM to produce seven channels of audio and one
synchronisation pulse to reference the channel timing.
The audio is sampled at a rate of 12.5 kHz by the TDM gates IC9/A and IC9/B. IC9/A
and IC9/B are driven by IC1.
The position of the audio channel varies depending on the requirements of the system. Its
position can be determined by attaching an oscilloscope at TP2.

Figure 19: Representation of the waveform as measured at TP2

IC11 on the Audio Interface PCB in the RF unit (drawing 04-03109), drives V3 and
IC6/A to generate the synchronisation pulse.
The TDM audio from TDM gates IC9/A and IC9/B is passed to the RF unit via SYS
AUDIO+/– on the CIB.
76
04-03423
Channels
Sync pulse
Audio (channel 3)
Time
NGT Transceiver System Technical Service Manual