GU Patrol questions - Part II: Two antenna coaxes?

Okay.

Now I'm a little confused. I'm guessing it is running a differential antenna or similar.

I've pulled the antenna lead from the back of the stereo & it's got two pins rather than the usual one in a traditional (non diferential) stereo.

Can anyone confirm that the second cable is a differential antenna (GU Series III ST stereo with single disk & tape)?

Thanks,

Dave