Continuous Tone Coded Squelch System or Privacy Codes allow the user to hear only transmissions using the same code on the same channel, effectively blocking out unwanted conversations.
"Continuous Tone-Coded Squelch System", also known as "PL" ("Private Line", trademarked term by Motorola), "Call Guard" (trademarked by GE), or "subaudible tone". A means of transmitting a tone along with your signal. This tone tells a receiver to open up its squelch so that the signal is received. This method is commonly used with repeaters.
Continous Tone Control Squelch System
(Continuous Tone-Coded Squelch System) - This is a sub-audible tone transmitted by your radio in addition to your voice signal. When it is equipped with a CTCSS decoder, a repeater will not function unless it hears the CTCSS tone and the "carrier" signal from your transmitter. Different CTCSS tones are in use for different repeaters or areas. These may be applied to input or output frequencies, or both. CTCSS tones are used to minimize the effects of co-channel interference due to band-openings causing reception of distant signals
ontinuous one oded quelch ystem. Uses subaudible tones or codes (DCS) to allow co-channel users to operate without having to hear transmissions directed to other users.
Continuous Tone Coded Squelch System, a subaudible tone system which operates the squelch (COR) of a repeater when the corresponding subaudible tone is present on a transmitted signal. The squelch on a repeater that uses CTCSS will not activate if the improper CTCSS tone, or if no tone, is transmitted.
In telecommunications, Continuous Tone-Coded Squelch System or CTCSS is a circuit that is used to reduce the annoyance of listening to other users on a shared two-way radio communications channel. Where more than one user group is on the same channel, (called co-channel users,) CTCSS filters out other users if they are using a different CTCSS tone or no CTCSS.