Yes,
It will scan all 50.
There should be decimal points I think in the upper left area of the led
readout. Each one indicates a bank. I think if you try and turn all banks
off then it will resort to the first 10 channels which would light the
leftmost decimal point. Hit the 20 button and it should then light the
decimel just right of the one earlier etc...
I'm not sure of an online owners manual but you may try www.mods.dk and
select uniden (bearcat) and then look for the manuals button.

Good Luck,
Ralph