Every Fire Marshal should know how to communicate over the Department Radio with the "mixer off." Which choice below contains incorrect information regarding this important communication method?
1) "Mixer off" messages can only be transmitted by mobile units.
2) Since information transmitted from the scene of an incident may be critical to all concerned, the Radio Dispatcher shall not switch the "Mixer off", unless specifically requested to do so by the unit transmitting the message.
3) If in the dispatcher's experience, he or she believes the mixer should be off for confidentiality purposes, the dispatcher will automatically turn the mixer off in all cases.
4) The Radio Dispatcher shall switch the "Mixer off" if the names and/or units of injured members are being received, and/or information associated with the transmission of a 10-41 is being received.