What We Found
Utah Communications Agency Network (UCAN) finished rebanding the last of their trunked sites (System ID 7202) in Utah on Dec. 10, 2008. During the several months-long process of rebanding all the sites in the state, we found that our older trunk-tracking scanners would continue to track Motorola 800 MHz trunked systems with some limited success without any upgrades. LCN channels 440 through 559 were configured to insert between existing frequencies creating 12.5 kHz steps and it has been these newly opened frequencies that have created the issues.
Scanners that cannot have their firmware "flashed" so that updated trunking tables can be entered will still continue to track, but will not "hear" all the frequencies. The frequencies that cannot be received by legacy trunk-tracking scanners while in trunking mode are those frequencies that start with 851, 852, 853, and have a "0" (zero) in the fourth decimal place. If the rebanded system or site does not have any of these frequencies in the frequency pool, legacy scanners will be unaffected in their trunking ability.
Of course, all of the frequencies can be entered as conventional frequencies and scanned as conventional frequencies, but the listener will not have the benefit of knowing who is talking and any "following" will be strictly coincidental.
Those scanners that could be upgraded so that edited trunking tables (custom band plans) could be entered had no trouble in the rebanding process once the "new" tables were entered. The custom band plans that are now general knowledge will allow scanners to trunk-track sites and/or systems that have not been rebanded yet as well as those that have been rebanded.