I am an authorized user on the state system, I was getting a scanner for the sole purpose of calls ingest so I could get traffic when I am out of range. Is all I need that dongle and software and not a scanner?
You may need multiple dongles, depending upon how much spectrum needs to be covered. A real call-ingest platform consists of enough SDR devices to cover all of the spectrum used by the trunked site. As an example, if a trunked site is using 851.1625 as the lowest frequency and 859.3125 as the highest freq, you are going to need enough dongles to cover that spread (where typical RTL dongles are going to cover around 1.5-2.5 mhz a piece. In the scenario I have painted you'd need at least three dongles. Or an Airspy. Or some other SDR that handles more msps and is compatible with applications that send to the call-ingest platform. Then again, you may be monitoring a trunked system that has all of their frequencies within 2 mhz of bandspread, in which case you can probably get by with one dongle.
IT's not for the faint of heart. You are dedicating a computer, one [or usually more] SDR devices (RTLs, Airspys, hackRFs, etc) and are requiring a way to get a good signal into each and every SDR in use on the system.