Uniden Bearcat UBC 248CLT Reference Manual page 36

Problem
Scan won't stop.
Solution
Adjust squelch to the threshold (Page 9).
Check the antenna connection.
Check to see if many of the channels are locked
out. If so, the scanner has less chance of finding
an active channel.
Review each channel's frequency to see if it is
correct and no memory has been lost.
It is possible that none of the programmed
frequencies are active at this time.
33