Narrowband/Digital ??

[Armadillo5]

So, if I wanted to listen to Narrowband, like DPS channels or some small town PD broadcasting on Narrowband, do I need to have a new BC796 or can I use my 780xlt?

Also, if I wanted to listen to, let's say a VHF Narrowband channel broadcasting in digital would I need a BC796?

Thank You for the help.