Here's all I got. I pulled some rando copy of the Whistler software that seems to work (at least it opened your attachment). The trunking stuff seemed OK, but I went in and pulled trunking site info using the built in tool in the software. There are a couple of sites that I've left locked out; I think they're just too far away. Try it without it at first. I simply think you're too far from a TACN tower site to get a good enough signal for long enough for the scanner to do its job.
One of the sites listed in RRDB seems to be missing some frequencies, based on the data from the FCC. I adjusted them in this file.
Good luck.
Remember: you're basic location (Cedar Bluff, VA) is basically at the limit of reasonable reception distance for a 7/800 MHz trunked system, assuming good line of site and no other distracting terrain. I just don't think you're going to be able to properly scan TACN from Cedar Bluff without an antenna that several hundred feet higher (if that's even possible) or without moving your scanner many miles closer.
One suggestion: Take the scanner and antenna and drive down to Bristol. Plug it in and see if it will scan TACN from there, as a way to confirm your programming is accurate (from a distance that we all agree would be easily within receive range).
