Well it's an antenna cable like this: https://www.amazon.com/Dipole-Antenna-ohm-PAL-Connector/dp/B00FQPHN2M (I literally just googled "ext ant 75 ohms"....)
I can't tell you what converter you need if you won't be a tiny bit more specific about what you even want to plug in.
Also your post is two times against the first rule of this sub:
Posts consisting only of a title/link will be deleted.