[time-nuts] lunatic fringe time standards

jimlux jimlux at earthlink.net
Wed Apr 14 16:50:21 EDT 2010


Eugen Leitl wrote:
> Hi -- a couple somewhat lunatic questions. Figured this would
> be the best place to ask.
> 
> Anyone aware of a time standard which compensates in regards
> to an ideal flat-spacetime-at-rest-relatively-to-cosmic-background
> reference clock? I realize this is not relevant for any affordable
> clocks.
> 
> Unrelated, anyone aware of a hardware (IC) counter which
> counts in a (local-bitflip) Gray code, so it can track a very
> fast (integrated?) oscillator without dropping cycles? 

Any synchronous counter won't drop cycles, right?  only ripple carry 
asynchronous have the propagation delay problem.

However, since long synchronous counters are complex, another way to do 
it is with a linear feedback shift register (LFSR).  Rather than doing 
it as usually drawn, with taps all getting xored to generate the single 
feedback, you do it using the output and feeding it "into" the stages 
(with an Xor) where the taps are.




> 
> P.S. Thanks for pointing me towards GPSDOs. Any European/German
> local alternatives to the Trimble Thunderbolt?
> 





More information about the time-nuts mailing list