[time-nuts] Frequency referenced temperature regulator
jimlux at earthlink.net
Mon Nov 8 15:35:15 UTC 2010
> On 11/8/2010 9:04 AM, Poul-Henning Kamp wrote:
>> But since I happen to have access to much more stable frequencies
>> than voltages, I thought of a different way:
>> 1. Mount a X-tal-osc with really lousy tempco inside the enclosure.
>> Has anybody tried that ?
> It's been my experience that oscillators with really lousy temperature
> performance have really lousy repeatability as well. I'm never delved
> into why this is true, but I suspect it's a number of things and not
> limited to the quartz resonator.
Depends on *why* it's a lousy temp performance.. is it that the crystal
has poor performance OR that the crystal is low Q (e.g. in a TCXO) and
the frequency is affected by the other component variations in the
circuit. There are some circuits where the bias changes with
temperature, and therefore, the power (and hence heating) through the
crystal changes, for instance.
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