I have an old 6500 Power Macintosh with a built in TV tuner with a coaxial connector. I want to have a bunch of Raspberry Pi's, the older ones with composite video jacks, each putting content on a different channel of the coax. There are expensive devices that only let me choose between channel 3 or 4. I want about a dozen composite video jacks each programmable to any tunable channel on the analog TV.