Here is some screenshots of why I love PC tuners. I have 16 tuners in my PC btw.
https://drive.google.com/open?id=0B7PjDRC3SaJxbnZxR2Y4VTlEWXM&authuser=0
https://drive.google.com/open?id=0B7PjDRC3SaJxYVZDdERKLUNMV0U&authuser=0
This is in Linux using my software, updateDVB, its 100% opensource. You can see in the background a spectrum scan, this helps you find tp much faster than blindscan (which updateDVB supports as well). Once tuned it analyzes the signal and parses everything so you can see it. It even looks for PIDS that arent assigned to anything, like in the second picture. Its a SD feed that isnt in the PMT/PAT or anywhere else. A STB will miss this every single time. every STB will.
UDL