The Slingbox requires a video source. This could be any kind of set top box(ie. VCR, cable box, DVR). Below is our FAQ page, it should answer any questions for you:
Hope this helps!
Ok I don't have cable I bought this because we have sling on our
computers/tablets and want to stream it to our TV. They said we had to buy
the sling player, chromcast and the sling player app which we did but it
does not work? Will a PS3 work?
Thanks so much,
On Tue, Apr 28, 2015 at 3:01 PM, anthony.sling <email@example.com>