Fixing a problem at 40 that stumped me as a 10 year old

A few months ago my parents gave me a box of my stuff they’ve had variously in attics and storage since I moved out in my early twenties. One of the things in it was my Sega Mega Drive — boxed, and with games and accessories. Unfortunately, I didn't have a TV that I could connect it to! The only connector packaged with it was designed to plug into the aerial socket of a CRT television. In the last…