You're still confusing things. There are three stages to this:
Signal source >>> Tuner >>> Display
Signal sources are OTA and Rogers Cable, both analog and digital.
Displays can be SD (ED) or HD and they may or may not include a tuner.
Tuners can be NTSC (analog), ATSC (digital OTA) or QAM (digital cable).
(Rogers may use encrypted QAM requiring a set-top box to decode.)
- HD and SD displays work with ATSC tuners for OTA only, but give the best quality
- Displays with cable-ready (NTSC) tuners can use analog cable directly, but you get analog quality
- Displays with QAM tuners (neither ATSC nor NTSC) can use clear digital cable
- Displays need a STB if there is any encryption in the cable signal, analog or digital
(Cable image quality will vary with bandwidth allotted, but never better than OTA today.)
A bit more complex, perhaps, but I hope you can see that the tuner must match the signal source, regardless of display.