Can you explain to me what a HDTV with QAM tuner is?

[davidsama]

Can you also tell me whether you can use a Satellite reciever with it or would i have to buy a Directv HD Satellite reciever?

[edDV]

QAM is the digital modulation scheme used for cable and has nothing to do with satellite.

Encrypted QAM is used for pay "digital" cable channels and requires a cable box or cablecard for decryption.

Clear QAM is unencrypted so can be received with a QAM tuner. The FCC requires the locals (primary channel) to be offered as clear QAM on cable. PBS has cable industry agreement to carry all local digital subchannels as clear QAM. Clear QAM channels can be SD or HD as broadcast.