This may have already been posted. In case it hasn't, here it is.
You can look up your existing wireless system and see what frequencies have been banned. http://www.fcc.gov/cgb/wirelessmicrophones/manufacturers.htm
There is apparently an internet source where one can determine the local TV station transmitting frequencies, based on Zip Code. Does any one know where it is?
I did find this bit of info...
Post-transistion UHF TV band(After analog shut off) :
Channel 14-51 = 470-698MHZ
Note that Channel 37(608~614MHZ) is not used for TV broadcasting, as it is allocated for Radio Astronomy.