Right, you probably already know this, but CLEMARS is a simplex channel, up to 100 watts. All the dispatch centers in my area, including the one I look after, all have CLEMARS on 100% of the time. B.O.L.O.'s and the like are broadcast from the biggest PSAP out to the two other ones in the county. When something comes out, our dispatch center will announce it on the main dispatch channel and the officers will switch their radios over to hear it directly. Our center and the other one in the county both acknowledge receipt.
So, like was said, it depends on where you go. In our area, a call on CLEMARS would be answered, more than likely. When we had a big fiber cut in the area a few years back, CLEMARS was the only way some agencies could communicate. It became a pretty busy "party line" for a few hours. With big antennas at 100 watts, it was no problem hearing traffic from all over the place. Most of the time it's dead quiet, but when needed, it pops into action pretty quick. Of course, the big motivation for that is all the agencies in this county are on VHF, so it's a good fall back. Agencies that do not dispatch on VHF are less likely to use it.
It's a great resource. Very basic, robust and it works very well. Too bad it isn't used more widely.
