IIRC in the F4, the target was usually detected using the god-like skills of the back-seater, and the intercept managed using the combined awesome, finely tuned crew cooperation of both crew members.
GCI and AWG11-12 helped a lot too (pre AWACS)!
In a later reincarnation, I once cleared a 'snagged' Bendix wx radar during a ground run on a Kingair, by picking up and tracking, on radar, an airborne target- Single Otter on floats at 7 miles, then visually acquiring same and pointing it out to the base engineer, who WAS impressed!
Fox2, Fox 2,splash one Otter!