The only CALTAC channel that I know of in Northern California is in Calaveras County. You may heard a dispatch on CALFIRE TCU Local (151.175), which can be heard in part of the Bay Area. CalTac is a non repeated, simples tactical frequency for communications on scene with in Calaveras County. They can also use the White channels, CAL FIRE tac channels. For example, a typical dispatch would be:
For Murphys Fire, Altaville Malones Fire, Vehicle Accident, Highway 4 at Redhill, Tactical will be Caltac, Time out 1745 hrs.
Hope this helps.