"The basis for the Coppertone RCA interconnect is a very simple but effective geometry: a tin-plated copper shield helically wound around a thin-walled Teflon tube. The jacket is a multifilament nylon yarn while the conductor is a pure copper solid core formed into a wave shape to be substantially suspended in air within the Teflon tube. This air suspension makes for quite low capacitance and quite high velocity. The RCA connector is a Rean NYS352G Neutrik utilizing gold-plated brass contacts. That's fairly common metallurgy at this level and in the Coppertone interconnect nothing to apologize for. The whole thing, soup to nuts, is made here in my workshop. I took the time to photograph one of the interconnects as I was working on it this morning so your readers could see how I make their cables. Here you can see the interconnect just before I ready it for termination, sitting atop my cork-covered workbench in the jaws of my work-tortured Panavise which is easily 20+ years old."

"Unique to Coppertone is my use of a helical winding technique for the tin-plated copper shield. It has 16 segments running clockwise and two elements counterclockwise to provide a different sort of coverage. I had a special double-decker braider built for me in Japan which allows me to shield on the bottom deck while simultaneously jacketing on the top deck. This capability is especially important to tack down a helically wound shield which would otherwise unravel if I had to move it between a shielding machine and a jacketing machine."

"Here's a fun photo of the construction of the Coppertone that helps illustrate its simple but elegant architecture. The 'nami' wave-shaping process is something achieved with a special tool I had made by Christopher Hildebrand of Fern&Roby whose Tektonics Design Group has outstanding fabrication capabilities. Here you can plainly see the 24awg pure copper nami conductor undulating gracefully through the thin-walled air Teflon tube. I learnt this technique from Alan Blumlein."

"Fairly straightforward termination into the Rean RCA. Don't ask about the solder formulation. It's a company secret. Makes a nice joint -:)"

Black Cat Cable website