[time-nuts] The 5MHz Sweet Spot

[Richard (Rick) Karlquist]

In a free running (non crystal controlled) oscillator,
the oscillator with the highest Q (regardless of frequency)
will have the best phase noise, if all oscillators are
normallized to the same frequency by ideal multiplication.
So the Q gain doesn't go away in that sense.

Having said that, in crystal oscillators, Q doesn't
determine noise in the first place, so the point is moot.

Rick Karlquist N6RK

On 11/1/2013 8:48 PM, Hal Murray wrote:
>
>> 1.  There is a theoretical QF product for quartz.  Being at 5 MHz  basically
>> doubles your Q, all other things being equal.
>
> Doesn't that Q gain from the QF product go away if you have to PLL it up to
> 10 MHz or 100 MHz which is what you really want?
>
> [I was about to ask why not go to 1 MHz, but Bob Camp answered that already.]
>