[volt-nuts] DIY JJ was Re: HP 3458A

[Mark Sims]

I looked into this some time ago...  JJ array chips are a commercially available product...  just send money.  
Apparently one of the bigger issues is making reliable contact to the chip that can survive thermal cycling.
I doubt that they are any more demanding tolerance wise than other semiconductor devices.

The problem with using high-temp superconductor JJ arrays is with the grain boundaries of the HTS material...  but the Russians have made HTS JJ arrays and standards.  At the time, there was a company that was very close to releasing a commercial liquid nitrogen cooled standard.
I don't remember any of the companies that were involved with any of the arrays, standards.