That adapter wasn’t for the antenna, it’s for connecting an iPod or other 1/8” headphone style source to/from a home stereo line in/out.
It looks like the stereo uses a “Sony 2-pin” antenna connector. The antenna lead you have is a Motorola car stereo type. I couldn’t find anything off the shelf but you can probably buy a female Motorola fm then cut the Sony antenna to connect the 2 wires though I’m not sure how you would know which is the conductor and which is the shield ground on that Sony plug. Wait, is the white wire on a single pin on that connector? If so then you’re probably out of luck.
Your best bet is a car stereo to replace or supplement that one.
