User's Manual

M7X and M7R Page 4-19 Installation
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Audio – Narrow-band (A) Connector
An 8-way RJ48 socket marked NB(A) that is used to connect the primary narrow-band audio and
signalling. All inputs and outputs are configurable to allow for system connection requirements. It can
also be configured to combine Guard signals simultaneously with the main receiver audio and squelch.
The pin-out is listed in Table 4-7.
The connector has an integral amber indicator that lights when the PTT input is active.
Note:
All line levels for this connector are equivalent to the average speech level regardless of the
waveform selected. The peak to average ratio of speech is taken to be 13 dB, whereas the peak
to average ratio of a sine wave is 3 dB. Therefore, sine wave test tones are expected to be
10 dB higher than line level setting.
An average speech signal applied at the same level as the line in setting (or a sine wave signal applied
at 10 dB above the line in setting) with the ALC off, will result in the transmitter achieving its specified
modulation level. Similarly, receiving a signal at the same modulation level as the transmitter specified
level, with the audio AGC off, will result in an average speech signal being the same level as the line out
setting (or a sine wave signal being 10 dB above the line out setting).