Retro OTA Broadcaster to send Composite Video + Stereo Audio to an old CRT that only has an antenna. Programmable via I2C for which channel frequency you want. (VHF, up to 3 channels switchable via the jumper block -- use only one jumper in the vertical position to select channel -- A maps to CLK0, B maps to CLK1, C maps to CLK2 when programming chip U3) Range is short, maybe 50 feet or so. Check legality of broadcasting on the frequency you choose to program it to. It's made to connect a short F-type coax antenna to for broadcasting, so a small extendable whip antenna will be fine. Uses a 5VDC 5.5x2.1mm jack power supply (1A or greater).
Based on the Isotope Engineering PiMod-Zero for the RF circuit, my Full Can Clock Oscillator project, and the Wideband RF Power Amplifier datasheet for chip U2 and antenna output on the board.
Not tested, boards and parts ordered.