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Common Radio Features
Smart PTT
Smart PTT is a per-channel, programmable feature used in conventional radio 
systems to keep radio users from talking over other radio conversations. When 
smart PTT is enabled in your radio, you will not be able to transmit on an 
active channel. If you try to transmit (press the PTT Switch) on an active 
smart-PTT channel, an alert tone will be generated, and the transmission will 
be inhibited. The LED will also blink red to indicate that the channel is busy. 
Three radio-wide variations of smart PTT are available:
• Transmit Inhibit on Busy Channel with Carrier — With this feature 
enabled, you will be prevented from transmitting if any activity is 
detected on the channel.
• Transmit Inhibit on Busy Channel with Wrong Squelch Code — With 
this feature enabled, you will be prevented from transmitting on an active 
channel with a squelch code or (if secure-equipped) encryption key other 
than your own. If the PL code is the same as yours, the transmission will 
not be prevented.
• Quick-Key Override — This feature can work in conjunction with either 
of the two above variations. With this feature enabled, you will be able to 
override the transmit-inhibit state by quick-keying the radio; in other 
words, two PTT Switch presses within the time programmed through 
radio service software (RSS) for Smart PTT Quick-Key Timer (default 
value is 1/2 second).