If you're looking for a handheld scanner primarily to monitor TACN in Bradley County, I would recommend the Uniden BCD436HP. The Whistler TRX-1 is touted to be a fierce competitior for the BCD436HP, but it has some fine adjustments that I have not yet been able to get set so that it will satisfactorily receive TACN in all Bradley County locations. Several of the well-informed participants in this forum have opined convincingly that the newly licensed EMA site for Johnson Blvd will actually be a TACN site. Whenever this happens, the performance of both radios should improve tremendously.
If you're looking to same a few bucks, you might want to look for a refurbished or used Radio Shack Pro 106. It currently does a fine job receiving TACN. It is not, however, a Phase 2 scanner. If considering a used Pro 106, check out the volume control carefully. If noisy, don't buy.