[volt-nuts] Is there a "standard" much better than a LTZ1000, but much cheaper than a Josephson Junction Array?

[Attila Kinali]

On Wed, 19 Oct 2016 21:14:42 -0400
Stan Katz <stan.katz.hk at gmail.com> wrote:

> Is US patent 6091281 just "whistling in the wind" or does it have some
> merit?

They do use the EFC voltage dependence of the frequency of an TCVCXO to
define a voltage standard. Yes, this can be done, but the variability
of the EFC voltage due to temperature and aging is at least in the low
ppm range. If one would use an OCXO instead, one could go below 1 ppm
temperature dependence, but I am not sure how good the aging behaviour
would be. Unfortunately, I couldn't find any information on the aging
characteristics of varactors. 

That said, this would be still only a secondary standard and would need
calibration against a primary. It would also be plagued by all the problems
OCXOs have, like retrace, vibration/shock sensitivity, etc.

So, IMHO it's a nice idea but probably not that much better than an
LTZ1000 and quite a bit more expensive (needs a good frequency reference
to measure the TCXO/OCXO)

			Attila Kinali

-- 
Malek's Law:
        Any simple idea will be worded in the most complicated way.