Maxon SD170EX Series - Page 15

Service Manual SD170EX Series
Page 15 of 38
Sub-audio squelch system
The SD-170EX Series can operate singly or with optional modem boards. Even if user wants to
use sub-audio SQ system, the radio will permit this SQ option according to some cases to avoid
confliction between sub-audio and data.
Contrary to general-purpose two-way radio, the input of the radio is data or audio. In case of audio,
its frequency spectra are limited to 300 ㎐ ∼ 3 ㎑ by internal BPF. So, the division of this and sub-
audio is possible on the frequency spectra because sub-audio has under 300 ㎐ frequency. But,
Data has wide frequency spectra compared with audio.
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