I don't have a BC250D, but I think it is fairly similar to the 796. Basically, you need to select a bank where the 1st 20 channels in the bank are not used. You need to press menu. scan option, trunk, then rotate the selector to get to the bank where you want to use. The select trunk type, ON, and LT(for the trunk type) Then go to the trunk channel, and and select the 1st channel in the bank.(I.E. 101,201, 301,etc)
Now you enter the the 1st frequency in the list from our database: 461.33750
Then press menu until you get back to the next channel number selection. Here you must go to the 4th channel in the bank and enter 461.41250
Repeat this until you have all the frequencies entered. Be sure that you put them in the channels 9, 13, and 17per the table:
http://www.radioreference.com/apps/db/?sid=4817
Now you can hit scan. I would hit the trunk button until you see the words IDseach. This will allow you to hear everything. Later, you may want to enter only the talkgroups you want to hear in the IDscan mode. We can help with that, but I suggest you stick with ID search for a while.
Now for the real question. You say you want to listen to transit ops, police and fire. I don't see any fire units on this system, and police are really just security officers. Most of the police, fire and EMS are on
State of Colorado DTRS I am not sure the 250 will receive this digital system, but that is for another post if you really want to try to program this system.