[volt-nuts] DIY JJ was Re: HP 3458A
phk at phk.freebsd.dk
Tue Aug 9 12:20:30 UTC 2011
In message <18.104.22.168.2.20110809070749.04f33918 at jefferson.edu>, "Marvin E. Gozum"
>This suggests that a volt nuts JJ would likely be when someone
>produces a JJ in a box that, like a Cs or Rb clock, still requires
>substantial upkeep and maintenance just as the surplus clocks are
>maintained by the time nutters, or Fluke standards maintained here.
The one thing I have never sat down and tried to calculate, is if
there is any reason in a high-temp superconductor JJ standard or
if the increase in thermal noise will make it a pointless exercise.
The reason I wonder is that the present standards have a very low
per "cell" voltage and therefore operates with thousands of cells
in series to get to 10V.
One way to counter that, would be to increase the stimulation
frequency from the current ~75GHz into the optical regime, since
(at least as far as I understand it) the voltage per cell is
proprotional with the stimulation frequency.
Then it starts to get interesting: A frequency stabilized semiconductor
laser (like in the CSAC) hitting a peltier-stabilized super-conductor.
If that is even possible, it would be considerably more amateur
friendly than liquid Helium and 75GHz waveguides.
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