In a quest to get an analogue tv modulator with NICAM Stereo encoding, I stumbled upon the MC44BS373CA modulator IC and a NICAM chip to go with it, the MC44C404. While, sadly, the MC44C404 isn't available (I don't know if any were actually made), the MC44BS373CA CAN still be purchased from the likes of UTSOURCE. I thought one of these combined with an Arduino or Raspberry Pi could make a great Analogue TV modulator. Maybe even combine it with a VBIT-Pi and make a teletext TV Modulator? And, of course, it still has that exciting NICAM input pin. Maybe somebody with the right skills in coding could use a Raspberry Pi to generate the required QPSK signal, which could then be modulated by this IC to make a proper NICAM signal. If you have any thoughts about this, email me at firstname.lastname@example.org.
The datasheets for these ICs are fairly easy to find, but here they are again anyway: