Connect tone

[schlermy]

Can someone tell us what a "connect tone" refers to?

 

[n2mdk]

They are subaudible tones like CTCSS that the radios sends out to connect to the trunked system. The frequencies are different from the PL ones and aren't important to scanners.
My description doesn't quite tell the whole story so you may get more of an explanation.

 

[WayneH]

When a subscriber radio on a Motorola trunked system is assigned an analog voice channel it must continuously send this sub-audible tone while transmitting its message. If it does not no audio will be passed and a timeout timer will eventually expire causing the transmitter to be shut off. It's purpose is to minimize interference and possibly a form of security too.