I have only one sensor, but the unit keeps scanning for three and sticking on sensor three, when the only sensor I have is on channel one. How do you stop the unit from scanning for other sensors. Also I cannot get the Atomic clock to sync up. And with the skimpy instructions I can't figure out how to change the year and date. When I press the date button on the rear, nothing happens...even if I hold it down for a few seconds.