Class 1B clear channels contain two 50000 watt stations, with directional antennas reducing interference with each other. These 1B clears do not have a protected area. Class 2 clear channels are primarily frequencies allocated as clear channels Mexico or the Bahamas. These generally contain numerous stations, many operating with very low powers. There will be a few higher powered stations with highly directional antennas.
Regional channels contain considerably more stations than do the clears.
Nearly all full power regional channel stations use directional antennas. On most regional channels there are several widely spaced dominant stations. Other nearby stations will be lower power or use a highly directional antenna engineered to reduce interference to the dominant stations. Frequently directional patterns on regional channels are quite sophisticated, because they are designed to reduce interference to several stations. The same action that resulted in the breaking up of the clear channels has also had an effect on the regionals.