[Elecraft] 10 MHz external reference - GPSDO

[David Anderson]

Dick,

I found the reference to that figure I quoted, it is in the K3EXREF manual:

The K3EXREF option locks the K3's reference oscillator frequency to an external 10 MHz source by automatically controlling the REF CAL function. While locked to the external source, the K3’s reference oscillator frequency is maintained within 2 Hz. Since the K3EXREF does not phase lock the K3’s reference oscillator, the external 10 MHz source has no impact on the K3’s phase noise performance. For best performance we recommend your K3 be equipped with the KTCXO3-1 high stability (0.5 ppm typ.) reference oscillator. 


73 from David GM4JJJ

> On 11 Mar 2016, at 16:55, Richard W. Solomon <w1ksz at earthlink.net> wrote:
> 
> I am a tad confused over this issue. Perhaps I need to read up on how
> Elecraft 
> controls frequency.
> 
> My understanding on a "Locked" frequency would infer that the result would
> be 
> a LOT closer than 2 Hz @ 10 MHz. 
> 
> Is there a detailed description of the process somewhere that I could read ?
> 
> 73, Dick, W1KSZ
> 
>