Hi folks,
I own a th78a which features a feture like the ringer we are talking about. The feature is very useful if you wish to leave the rig turned on waiting for a call from a specific person or persons. My wife and I have used the feature on a simplex frequency. We set both radios to a specific pl (ctcss) tone and also set the dtmf pager function so that the receiver would not wake up until both the correct pl and the correct three touch tones were received, at which time the unit would beep at me. Using both the pl and the dtmf page functions open the receiver and cause the radio to "ring" kept it from reacting to any old signal that might have come along.

73

Ron
n6msa