Need help identifying a Phantom store

I was perusing through the defense media archive (VIRIN: DN-SC-83-05208) when I stumbled up this picture.

The caption reads, “A left side view of an F-4 Phantom II aircraft with advanced medium range air-to-air missiles (AMRAAM) underits wing, in flight over the Pacific Missile Test Center.” However, this store looks neither like the Hughes or Raytheon AMRAAM entires. It looks either to be a tactical information relay pod of some sort or a big bore short range missile.

If anyone could help me identify it I would much obliged.