QAM

A (clear) QAM tuner is becoming a dinosaur these days since most are scrambled digital. The FCC removed the 'Clear QAM' proviso several years ago and most if not all the name brand cable suppliers require their flavor of STB to work at all. Anyplace you find Clear QAM or NTSC (analog) the CG likely has a small head end in the office to supply the property with decoded cable or remodulated OTA. The FCC requires an NTSC & ATSC tuner but don't think they have any QAM requirements for the above reasons.

If those TV's really don't have a QAM tuner, I'd replace them.. Also, make sure your external antenna works properly when the CG can't deliver.