[time-nuts] State of the art of crystal oscillator measurements

[John Miles]

> If the oscillator output is thru the resonator, then at large offsets,
> the source impedance is reactive.  It can easily have an effective
> temperature less than room temperature.  If this "source" is then
> used with a low noise temperature preamp, it is entirely possible
> to go beyond these supposed theoretical limits that are based
> on T=300K.

Sure, until you try to measure it with a Zo=50R instrument, or otherwise do something that involves putting real power into a load.

-- john, KE5FX
Miles Design LLC