[time-nuts] Low phase noise VCO

[Nick Foster]

> Does it need to be phase coherent with your 10MHz reference, or just frequency locked?

Doesn't need to be coherent right now, but I can think of several reasons why having it phase coherent would be helpful in the future. 

> Also,  If you are using it in a software defined radio, you don't necessarily need *control* of the oscillator frequency.  What you might need is *knowledge* so that you can set the correct number into a DDS/NCO.  
> 
> Knowledge (especially against an external 10 MHz source) is a lot easier to come by than control: all it takes is a counter.
> 
> This lets you choose an oscillator with great performance in the short term (high Q resonator) without having to worry about temperature compensating or adjusting (both of which require a lower Q, so you have something to adjust).

That's a great idea, but in this application, it's sort of painful to continuously update the SDR with counter information in real time. Part of the impetus for doing this is to use the SDR itself as an accurate frequency counter.


--n
 		 	   		  
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