[time-nuts] New topics (was Re: He is a Time-Nut Troublemaker....)

[Magnus Danielson]

John Ackermann N8UR skrev:
> Magnus Danielson wrote:
> 
>> This diffrential locking technique could be applied to atomic standards, 
>> but then naturally require much improved solution than simple 
>> oscillators. The diffrential locking technique does not magically solve 
>> issues that is typically common mode, such as temperature dependence. It 
>> can however even out individual properties like noise and systematic 
>> drift to some extent. It essentially runs the oscillators as a common 
>> constellation and attempts to achieve the average improvements of those 
>> oscillators in an interlocked fashion. In its simplicity it will do 
>> unweighed averaging. It is fairly easy to do weighed averaging by 
>> individualizing the feedback gain to the respective oscillators. Further 
>> refinements would individualize the proportional and integrate feedback 
>> terms, but as always, the simplicity forms a limit.
> 
> Assuming that the atomic standards are correct for some tolerance of 
> "correct", I'm not sure why you would need to use a differential locking 
> scheme (or anything else that moves one oscillator versus the other) -- 
> if you simply mix the two signals together you get a sum that contains 
> both signals.  Apart from redundancy (what if one unit fails), why not 
> just use that sum to drive the clock?

Because they _WILL_ drift appart.

Interlocking them force them to a common frequency and average phase.

Cheers,
Magnus