They may have switched over to the White-3 channel, 44.92 base. Give that a try. Otherwise, I'm guessing the mobiles are being repeated on a local tower, perhaps at the area office in Ukiah, and the base is transmitting from a remote mountain tower that you cannot hear. Since most of their activity is in and around Ukiah, I would think they would be using a local site you can hear. You also may just need to find a "hot spot" in and around your home to pick up a good signal. Portables aren't the best low band receivers.