#781

WBBM-AM Employees and listeners perhaps. :P

Most of the 3 digit numbers that are of any importance around here are gone, except one.

#224 (overlay)
#630 (DuPage and most of Kane County)
#773 (Chicago outside the Loop area)
#708 (western and southern Cook)
#312 (Chicago Loop)

That leaves

#847 (northwest Cook and Lake)
#815 (surrounding area)