The only requirement is that your scanner is VHF-Hi capable.
I have never seen a scanner that does not have VHF-Hi in it. Today's modern keyboard-programmed scanners all have the VHF-Hi band in them. The VHF-Hi band is between 137 MHz and 174 MHz. The FCC has allocated the 160-162 MHz range to railroad communications. NYS&W also uses 457.9375 MHz for the end-of-train telemetry. I program this frequency in as well since hearing the chirps from the E-O-T can help you locate a train if you're out chasing. The E-O-T's are low power, you'll usually only hear them within a mile or two of where the train is but they've tipped me off numerous times. Most other railroads use the same E-O-T frequency as well. I've also seen 452.9375 MHz listed for E-O-T's but the railroads I monitor use 457.9375 MHz.
Besides being a railbuff/model railroader I'm also a licensed ham as well as a scanner listener and all-around radio buff. I have 2 ham radios and 6 scanners in the radio shack at my house.
If you have any other radio questions feel free to post them.
