[time-nuts] Modern signal generators

[Richard (Rick) Karlquist]

On 12/11/2018 9:13 AM, djl wrote:
> Rick: I've spent some time with the dds blocks. We found them to 
> generate lots of low level spurs, making lots of "birdies" when used as 
> local oscillators in receivers.
> We had better results using:
> https://www.silabs.com/products/timing/oscillators.
> 

I was talking about making a programmable frequency synthesizer
with a DDS, to use as a general purpose signal generator.

A silabs part functions exactly the same as a crystal oscillator
once it receives its one-time programming at the factory, AFAIK.

Of course a crystal oscillator has better spectral purity than
a frequency synthesizer.  But it doesn't make a signal generator.

Am I missing something?

BTW, you can do even better than Silabs with an actual crystal
oscillator such as those made by Crystek.

Rick