Only the 2 tuner models, name wise, its just labeled "Premiere"
The 4 tuner models named, "Premiere 4" is for digital cable only.
For older models, Series 3, they all can do both OTA and cable, all 2 tuners as well.
For new models, the Roamio, only the 4 tuner model will support cable OR OTA. The 6 tuner Roamio models only for digital cable.
Original S1 (Recycle Heaven)
Series 2 (PLS, sold)
TiVo HD (XL, PLS, "652")
Juliet Basic (4XL, PLS)
The TiVo Apocalypse begins on Sat 2013 Feb 16 00:00 GMT!