Duct Tape half the screen off and watch the other half. That's the part your tax dollars paid for. You can adjust the % of screen covered for what the real number is.
Meanwhile I pay for cable and get to watch adds to boot. Over the air and public is sounding better all the time.
PBS isn't a good example of a model where a few pay while many use. True, they get money from the begathons, corporations and foundations, they also get a lot of tax dollars from federal, state and local govts. Since I get taxed by those entities, I am paying for PBS. In fact, I might be paying more in taxes than I do for products that advertise commercially on the non-PBS channels so I feel zero guilt in watching a PBS show.
Interestingly, I've watched more PBS this year than I've done in years because I've now got a 65" HDTV (and no cable/FIOS/Satellite). The OTA HD broadcasts of the Philly PBS station are often visually stunning. The flies on a carcass in a nature show look so real.