If a given antenna works well on one scanner for certain frequinces, it should work well on a newer scanner for the same frequencies. Any different scanner from the original one you were using it on could be more or less sensitive in of itself, so it may be hard to tell if any gain or loss in performance was due to the antenna or the scanner itself. As far as the new technologies if you have enough signal to hear the voice you should have enough to hear a control channel for a trunk system. So if that antenna used to bring in conventional voice traffic in the UHF band nice and clear it should bring in a trunk system in the UHF band with a similar strength signal. As far as digital goes I have found a so-so antenna sometimes does not cut the mustard. In a mobile situation I found a fair improvement going from a mag-mount to drilling a hole and getting a proper groundplane, using the same whip. YMMV
