Kenwood TH-77A Service Manual page 17

IH-77A/E
Device Functions
Reference No. Function Description
Cross-band repeater AF switch AF output signal in sub-band is input to microphone amplifier.
5-V regulator Used for microcomputer and power circuit reference voltages.
Backup detection
Microcomputer Power and signaling control
DTMF decoder IC
Microcomputer Display, key entry, and DTMF signal generation
CTCSS unit power
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