[time-nuts] Thermal impact on OCXO

[jimlux]

On 11/4/16 6:56 PM, Bob Stewart wrote:
> In the general case, is the impact of changing the ambient temperature around an OCXO from, say, 40C to 41C the same as changing it from 41C to 40C all else being equal?  IOW, if I somehow have the same temperature ramp over the same time period in both directions, will I wind up with the same frequency and phase, or will the frequency revert but at some phase difference?
>
most oscillators exhibit some degree of hysteresis - the mechanical 
mounting puts stresses on the crystal, if nothing else.