Assuming that it's an LTR standard system, the Pro-92 doesn't require that you enter the system frequencies in any order. It does trunk a little more effectively if you enter the freqencies in logical channel number order for an LTR system that has more than a few frequencies. You can mix conventional and LTR frequencies in the same bank.
The 92B, in general, did a better job of following Motorola trunk systems since it uses control channel handshaking instead of the subaudible tones of the original 92. This isn't true of all Moto systems though, and the original 92 did a better job with some Moto systems than the B model, in my experience. Another downside of the B model is that it won't trunk track with rebanded Moto systems since the control channel data won't be correct for the new band plan and there aren't enough tables to compensate for the change. The original 92 should still work on rebanded systems since it's only dependent on subaudible tones. The Pro 95 doesn't do LTR trunking so, if that's your main use for the scanner, the 92 is what you need. For $65, it's hard to go wrong if the unit is in good shape.
