[time-nuts] C-Max Receiver Experiment

Hal Murray hmurray at megapathdsl.net
Mon Oct 31 05:23:26 UTC 2011

> Based on several suggestions here, I think the next thing I'll try is
> capturing actual event arrival times.  That will allow me to plot a
> histogram and let the experiment run all night (and day) to take advantage
> of different local times.  Plus it gives me an excuse to buy (or build) a
> universal counter. 

I'm assuming you have a TBolt or similar to use as a reference.

I think one of tvb's picPET's and a PC with a serial port is all you need.

You probably need two of them (and 2 serial ports) so you can compare the 
WWVB pulses with the PPS from the TBolt.

You could do that with a switch, assuming the WWVB pulses are late enough to 
be easily separated from the TBolt PPS.  If things are stable enough, you 
could just flip the switch by hand, say once or twice a day for a minute or 
two.  If not, you could use a bit from the printer port to drive a mux.

If you have the PPS kernel support in your OS, you could also do it without 
the picPETs.  Again, it either takes a switch or a second serial port.


I think the real question is what will the adev graph look like?  Long term 
it will be good, but how long, and where will it cross over what you are 
trying to discipline?  I'm guessing it will take several days, maybe longer.  
That might fit well with with a recycled rubidium.

These are my opinions, not necessarily my employer's.  I hate spam.

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