[time-nuts] Synchronisation of crystal oscillators

[Bob kb8tq]

Hi

Well, there goes Barkhausen …. :)

https://en.wikipedia.org/wiki/Barkhausen_stability_criterion <https://en.wikipedia.org/wiki/Barkhausen_stability_criterion>

Bob

> On Mar 1, 2020, at 8:58 PM, Alex Pummer <alex at pcscons.com> wrote:
> 
> don't forget the  oscillator is one amplifier with infinite gain on his own frequency
> 73
> KJ6UHN
> Alex
> 
> 
> On 3/1/2020 2:46 PM, Richard (Rick) Karlquist wrote:
>> 
>> 
>> On 3/1/2020 2:28 PM, John Moran, Scawby Design wrote:
>>> My apologies if this is slightly off-topic, but it does concern crystal oscillators.
>>> 
>>>> However, I then remembered Huygens's discovery that 1S pendulums mounted on the same wall, or beam, would synchronise and swing either in phase, or out of phase and sometimes one would be stopped, by the minute interactions.
>>> 
>>> So, my question is - will my row of low frequency crystals 'talk' to each other and synchronise in their frequency groups as well? Remember that these crystals are long thin bars of quartz - one of the 3,600Hz crystals being 2mm square by 60mm long - so they will possibly vibrate quite vigorously compared w
>> 
>> Injection locking requires that the oscillators be within each
>> others 3 dB bandwidth, or at least close to that.  Oscillators
>> on different nominal frequencies are no problem (EG 3 MHz and
>> 10 MHz).  Even two "10 MHz" oscillators won't lock unless they
>> are adjusted to close to zero beat.  OTOH, if you carefully
>> adjust a couple of HP10811's to zero beat, you will have to
>> go to extraordinary measures to keep them from injection locking.
>> A lot more than just running them on individual voltage
>> regulators.
>> 
>> Bottom line: probably not worth worrying about for your
>> hobby project.
>> 
>> Rick N6RK
>> 
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at lists.febo.com
>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>> 
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.