[time-nuts] Running voltages through MVAR (In re: HP5065)

Magnus Danielson magnus at rubidium.dyndns.org
Sun Aug 23 15:58:58 EDT 2015


Using ADEV and MDEV, and indeed TDEV as TVB points out, for analyzing 
other physical signals than phase/frequency is maybe not very common, 
but if Kocher if you know your field well enough.

David Allan and I discuss this every once in a while. ADEV/MDEV and 
friends is really the statistical tools to analyze and separate noises 
of different slopes. Together with the bias functions you can use it to 
verify you have the white noise you assume, and only then you can 
rightfully make use of that property to meet the intention of GUM.

Flicker noise is indeed one such noise-form that does require better 

Don't forget to use FFT as well as analyzing non-repetitive systematic 
trends. I'd love to see the raw data more closely.

So keep up the good work.


On 08/23/2015 08:16 PM, Poul-Henning Kamp wrote:
> I have decided it is finally time to come clean about one of my
> "trade secrets":  I sometimes run voltages through MVAR.
> Sometimes I also run temperatures, kilowatts and anything else
> I happen to have a time-series of through the MVAR.
> In this case, it tells us a lot about why the C-field current of
> my HP5065 is unstable:
> 	http://phk.freebsd.dk/hacks/HP5065A/20150822_mvar/index.html
> I'm not done collecting data for the resulting effect on the HP5065
> performance, but so far it looks like the MVAR floor is half of
> what it used to be.

More information about the time-nuts mailing list