[mythtv-users] Hauppauge Win TV HVR USB Stick

Brian Wood beww at beww.org
Thu Aug 9 08:43:58 UTC 2007

On Wednesday 08 August 2007 22:51, DaveD wrote:
> Probably wont work with cable digital channels, which, I believe, are
> usually QAM (Quadrature amplitude modulation).  I think that
> over-the-air is strictly FM (Frequency Modulation).  It is conceivable
> that the cable company provides over-the-air type signals, but our cable
> company (Comcast) is into maximizing profits, and for that, they need to
> get as many channels crammed down the pipe as possible and QAM enables
> LOTS of channels on a single wire.

ATSC and NTSC (the two presently-used OTA systems) are both amplitude 
modulation schemes (vestigial sideband).

I'n not aware of any cable system that sends ATSC down the wire, they pretty 
much use QAM56, for the reasons you mention.


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