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

Ed Palmer ed_palmer at sasktel.net
Sat May 11 12:29:33 EDT 2013

On 5/11/2013 5:32 AM, Magnus Danielson wrote:
> 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?
> Neither.
> Instead of added wideband noise-modulation, think about more 
> systematic noise.
> 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. :)

Of course, they'd reference it to a cesium fountain!


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