[time-nuts] GPSDO time constant

Magnus Danielson magnus at rubidium.dyndns.org
Thu Jan 8 06:50:01 EST 2009

Poul-Henning Kamp skrev:
> In message <4965DC62.9070205 at rubidium.dyndns.org>, Magnus Danielson writes:
>>> In a lab setting, it makes sense to increase over the default
>>> time-constant, just remember that it impacts your loops ability
>>> to cope with for instance a 2g turnover.
>> Most labs would have issues with a 2g turnover. :)
>> Flipping oscillators that runs is evil and should be avoided at all 
>> times. Should be in the rulebook for time-nuts.
> Correct, but it is perfectly normal behaviour for telecom techs
> who remodel installations while running, so the products must
> cope with it.

True. Very true. The only thing which to some degree prohibits that is 
to make them monolithic. You are not entierly safe even with monolithic 
racks. Ericsson created a rack system in which the bottom of the rack 
was actually forming a closed container with the floor. Hook up 
compressed air to the nossle and the rack was floating, and hand-pushing 
the rack into position was no trouble, pull the plugg and it would sit 
tight on the floor again. That way they could shift in their racks while 
running, making cut-over time go down to zero.


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