[time-nuts] Tbolt issues

Charles Steinmetz csteinmetz at yandex.com
Thu Sep 1 16:26:48 EDT 2016

Tom wrote:

> No, again it sounds like you have a bad TBolt. Or something is wrong (antenna? reception? time constant? environment? China resoldered parts?). I appreciate that Juerg did lots of testing -- do you happen to have his ADEV plot?
> Your claim of 1e-10 is order(s) of magnitude worse than the TBolts that I see. Something is wrong.

I second that (not that any further evidence is necessary following 
Tom's comprehensive response).  Additionally, as far as I know, the 
units Tom was testing would have had the default tuning parameters (Tom, 
please comment).  Most Tbolts I've seen can be tuned for much better 
performance than this at tau > 100 seconds, if they are equipped with a 
37265 OCXO.

Note that the Tbolt has tuning parameters that limit how far the 
frequency is allowed to wander to adjust the PPS phase -- if Bert's 
unit(s) have these parameters set to allow very fast PPS recovery, that 
could well cause the behavior he describes.

You should also check all of the other tuning parameters to see if there 
are errors in the settings.

However, rather than mucking about in the myriad tuning settings 
starting where they are now, I recommend doing a full factory reset to 
get all parameters back to the original settings.  Then (after several 
weeks of undisturbed running), compare ADEV performance with Tom's graphs.

Best regards,


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