Close, but no cigar! Look at the pathetic MacTV.
As to the notion of using the 512k, You'd undoubtedlyly have LOTS of RFI problems to iron out, like damping emissions picked up from the MoBo, telegraphed thru the chassis and exiting the case via the whip antenna you've spec'd! No way such a rig could get a home rating from the FCC considering the internal structure of the FatMac.
This is just a W.A.G. but I'd put money on the fact that it required a modularized design with INTERNAL RFI shielding in a mostly plastic chassis/shell to get the MacTV past the FCC roadblock for home use.
Sorry to be a killjoy . . . :I
jt =8-/
p.s. . . . but it IS a nifty concept!