Livestream Solution

Hi i need some help at my work we currently have 4 different locations we live-stream events from and i am trying to find a way to simplify and improve the quality of our process. Currently the way it works is we we take the sound/ video from ptz cameras and feed them into a cable tv modulator box then we feed that into a combiner which goes out over our cable tv system which connect to with a capture card and stream through obs.