VAX 7700 CPUs, CI cables

OK I found some hanks (chopped up from computer room removal) of old blue "thick" CI cable. I was actually gonna take it home and use it for some recabling of my radio station anyway when this subject came up on cctalk. Externally it is 0.4" like many RG-8 and RG-213 types. Internally the center conductor is 11AWG, silver plated solid copper. Yep, silver plated. The dielectric is 0.238" diameter polyethelyne foam. Again, a little smaller diameter than usual for RG-8 types, but I think in ratio with the inner conductor being smaller and the properties of foamed poly, gives 50 ohm impedance. Then, the amazing thing is what's outside the dielectric. There is a layer of foil, a THICK layer of braid, then another layer of foil, then another THICK layer of braid. I don't think I've ever seen a RG-8 type coax with 4 layer shielding. Most RG-213 types have a single thinner layer (and some have foil). I don't think the braid is silver plated, I think it's just tinned, may test that out later.