Good day fellow hifi Dudes
It is the refrigerant feed pipe found in coils, small bore and approx. 4mm OD, it has a thin wall and is the normal OFC copper (well all copper is OFC if the truth be known but it’s a marketing hype thing). It needs to have an insulated central positive conductor fed through the centre and then soldered (or better screwed down) into the RCA's. No dielectric needed for the tube, only the central live connection and if you use magnet wire with its enamelled coating, hey presto it goes through the tube really easily. Low friction PTFE sleeve heat shrinkable has been used as has cotton. The last time I made these was 10 years ago at least and it helps in really noisy (EMF etc) areas with lots of taxis etc cluttering up the airwaves.
I actually prefer to use these as speaker connections due to the super low resistance and large surface area. It can really tighten up the bass nicely for beer money, the two conductors would need to be air gapped in this application and there are plastic clips designed for this sort of thing. Not being in the know locally regarding suppliers I am guessing that a plumber’s supply would be the go for sourcing it. From memory it came in 20mtr reels (smallest) but that was back in the UK. The diameter allows it to be screwed down directly into the majority of speaker terminals and amp output further saving additional cost on dafty connectors which just add to the general mess of most hifi designs where a wire is a wire!
I and many others compared this at club shootouts and it aced some very expensive jobbies indeed. Best application was DAC to transport which surprised me as 75 ohm was supposed to be the ultimate but I guess when you really look into it most RCA plugs and sockets come out nearer to 20 ohms characteristic impedance so not matched properly anyway. I will dig the camera out later and take some piccies. In the meantime just buy the 50R microwave rigid and try it, the steel inner can bring a bit of steeliness to the sound but in a lazy valve setup can actually make it sound considerably faster would you believe. Experiment and have fun, that’s what this hobby is all about.
I fell off a roof today helping a mate out so typing one figure mode, ouch bloody ouch.
IMO IMV IMOO my experience and that of others, just to keep the SNA wonderful persons happy.
Vitavoxdude