December 4, 2013

FCC Technician Exam Question Of The Day (T2B02)

Q) What is the term used to describe the use of a sub-audible tone transmitted with normal voice audio to open the squelch of a receiver?


NJ2X Notes:
Continuous Tone-Coded Squelch System or CTCSS is used to reduce interference on a shared two-way radio communications frequency.  Instead of opening the receive audio for any signal, CTCSS causes the two-way radio receiver's audio to open only in the presence of the normal RF signal and the correct sub-audible audio tone (sub-audible meaning that the receiver circuitry can detect it, but is unheard by the users in the audio output).

Kenwood TH-F6A has built-in Continue Tone-Coded Squelch System (CTCSS)