I played a bit with the firing range charts...
Against a MiG-17...
90% chance of detonation from radio proxy fuse, is at 73/116m (5E11/5H49)
50% chance of detonation from radio proxy fuse, is at 98/155m (5E11/5H49)
20% chance of detonation from radio proxy fuse, is at 110/175m (5E11/5H49)
Against a B-52, 20% chance of detonation from radio proxy fuse, is at 300/485m (5E11/5H49)
Against an F-4, 20% chance of detonation from radio proxy fuse, is at 170/270m (5E11/5H49)
Against an F-117, 20% chance of detonation from radio proxy fuse, is at 20/30m (5E11/5H49)