Channel Busy Lock is a privacy feature that keeps communication lines open by preventing radios from listening or transmitting through conversations outside their talkgroup. Whenever the radio is not allowed to talk, you will hear a busy tone if you try to transmit.
We all know that the conditions for a normal analog walkie-talkie communication are nothing more than frequency carrier and CTCSS/DCS, that is, two walkie-talkies with the same frequency and CTCSS/DCS can communicate completely.
When the transmitter turns on the channel busy to lock the selected carrier, it means that other walkie-talkies except the transmitter will receive a busy tone when transmitting on the same frequency as the transmitter. In the same way, if the channel is busy locking and selecting sub-tone, it means that in addition to the same frequency and the same sub-tone, the walkie-talkie other than the transmitter will also receive a busy tone when transmitting.