[red16v]

Many thanks for the link. I used to work in the communications cable industry and found much of it pertinent to my time in it during the 1970's. We used to make 174 &375 'solid' coaxial cables for the PO. By solid I mean the outer was formed by taking the required width of copper tape, using a former to turn it from flat strip into a 'butt' rounded outer with air spaced insulators inside - about the size of a shirt button on the 375 cables. Individual tubes would then be wrapped together to form the basis of the final cable before insulation was applied over the whole lot. I certainly recall 18 tube 375 cables and 4 tube 174 cables.

I was involved, in a small way, in the HF testing of a large experimental 18 tube 375 cable laid between Martlesham and the PO tower in Birmingham. Happy days going between manholes in the suburbs of Birmingham, pumping out the chamber and getting the cable jointers to connect up the test kit whilst I stayed nice and warm in the van with the homemade TDM test kit (You couldn't buy that that sort of test kit in those days). Lovely bacon sandwiches.

We also had production facilities for flexible (think TV) co-ax - Italian bit of kit. Was a real wonder to see it in action, no-one could work out how it worked! All these bobbins of copper wire flinging around some sort of inner at some horrendous speed - can't see it would be allowed these days! Think of something like a horizontal maypole.

Thanks for bringing back the memories.