[time-nuts] Good clean-up oscillators

[jimlux]

On 1/23/19 9:22 PM, Richard (Rick) Karlquist wrote:
> 
> 
> On 1/23/2019 7:59 PM, jimlux wrote:
> 
>> My idea was to get an OCXO without the oven (or with the oven 
>> disabled) - the idea was that an OCXO will have high Q for good phase 
>> noise, and I can deal with the frequency shift due to frequency and 
>> aging in the long term in other ways
>>
>> As it happens, it's hard to do in practice (it makes your unit more 
>> "custom") because OCXO mfrs don't conveniently bring out oven and 
>> oscillator power separately.
>>
>> So it's probably not available as a standard item, but you could 
>> probably get an SC cut crystal and put it in your own circuit.
>>
> 
> The 10811 brings out oven and oscillator power separately.  However,
> if you don't power up the oven, the crystal will be way off frequency
> so your idea is a non-starter.

And, of course, it's in a place on the frequency vs temp curve with a 
large slope.

The large frequency error might be tolerable in some applications - if 
it's going to feed a synthesizer of some sort, then it's a matter of 
reprogramming the synthesizer. Or if you're doing timing, and you don't 
care whether the oscillator is 9 MHz, 10 MHz, or 11 MHz, just that you 
know what it is.




> 
> Rick