Nothing quite that complex. In December, when the county fire association - which own's the repeaters that operate on this frequency - made the conversion to narrowband, the decision was made to change the output tones of the repeaters to a common tone. This allows all units in the county to hear all traffic on the frequency. In the past, there was occasionally issues when a unit operating on one repeater would not realize that there was traffic taking place on the other repeater. The repeaters continue to use seperate input tones, which allows the operator of the mobile unit to choose the repeater which give the best coverage in that particular location, but still hear traffic on the other repeater.