Please take a look at this nomen plate: http://imagehost.vendio.com/bin/viewimage.x/00000000/juliettej/nvr3.JPG This is on a 3rd-generation ATA set. The 3rd gen sets are built on AN/ARC-5 chassis (screw-on roller coil plate), instead of a 274n chassis. They are rare sets. I've seen three of them, all 2.1-3.0. Has anyone ever seen this order number in any frequency range other than 2.1-3 MC?