#768

Episode 768
I upgrade my twinax cable (two wires in one shield) to a triax cable (one wire in two shields). I find out some triax connectors have two lugs and some have three lugs.
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[@justinjohns579]

Cool Video. I work at Keithly and can confirm that yes that connector is for a special sma cable with guard and shield, just like a standard triax but thiner and semi stiff. We use it for SMU connections on the 4200 series parameter analyzer. if you search 4201-SMU on google you can find images of the card.

[@InssiAjaton]

We used to call our two wires/one shield cables and connectors TWIN BNC. The connector had the insulation core split, the short half had a pin and the longer insulation half housed a socket. Of course, the panel and the cable connectors had to maintain continuity of the wire colors, so the panel one had color “1” on the pin, and the cable one had color “1” on its socket. Color “2” was the opposite. In that way, the whole “BNC” was polarized for differential signaling with an end to end shield. Our use was for communication between a hand held pendant and the main controller box. The connectors did not need more than the usual two outside lock pins. You could not mix an ordinary BNC and the TWIN BNC anyway, due to the internal mating surface difference.

[@oriole8789]

Haha very nice find. Triax/twinax/quadrax connectors aren't too hard to crimp as long as you have the tooling - which is very expensive. I've had similar experiences with Arrow. I work with military stuff a lot and at some point I needed a particular mil connector. They were something like $80 a piece normally, but then I saw that Arrow had cheaper options.. which happened to be space-grade outgassed versions of the exact same connectors. They came in their own boxes with space-grade labeling, with full outgassing and compliance reports. On Arrow, they were something like 30% cheaper than regular versions of the same connector. Physically identical of course. I have no idea how Arrow derives its prices - they seem all over the place sometimes. I sure hope that distributors aren't getting screwed by Arrow in this way, where they'd have to absorb the cost of these pricing mistakes. The business models of some of these larger businesses can be absurdly inefficient at a low level, even if they are reasonably profitable on a macro scale. Something something capitalism. It's the norm. ;)

[@herbertsusmann986]

I wonder if you could make your own triax cable by taking some good coax and then push some braid from another coax over the first coax. Maybe then put heat shrink over the outer braid. You can compress braid pretty well so it will fit over a larger diameter. Connectors are still an issue I suppose.

[@bobkozlarekwa2sqq59]

Sounds like RG-142BU. I use it for making baluns

[@jdmccorful]

P.T. Barnum strikes again.Thanks for the look.