[time-nuts] A Time-Nut's Worst Nightmare

Magnus Danielson magnus at rubidium.dyndns.org
Sat May 11 07:32:53 EDT 2013

On 11/05/13 06:48, Jim Lux wrote:
> On 5/10/13 6:52 PM, Ed Palmer wrote:
>> Part of me thinks it's cute, part of me wants to kill it. :-)
>> https://www.tindie.com/products/akafugu/vetinari-clock
>> Ed
> but.. what is the actual distribution? Is it white phase or white
> frequency?


Instead of added wideband noise-modulation, think about more systematic 

Notice how it only affects on every second. Also note how after lagging 
it makes huge jumps. Also notice how it does not jump backwards.

What it tells is is that it makes a random decision wither to jump 
forward or not, and if to jump forward one sec or the error sec. Keeping 
the amount of time it lags, it can then every now and then jump into 
place. It would make sense to have a maximum lag so that it is forced to 
jump into place. There is a practical amount as to how high speed you 
run the handle without there is a risc of it skipping past the intended 
second without you noticing, so let say that it does not do more errors 
than 5 seconds or so to keep it manageable.

The end result will be a clock which in long term is showing the right 
time, but have short term variations. Since it is a lag scheme, it will 
also on average be behind.

Not to hard to achieve with a PIC and not to hard to implement, but 
highly annoying none the less.

Looking forward to seeing NIST having one of these in their lobby. :)


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