[Elecraft] K3S new synthesizer query

[Don Wilhelm]

Brian,

The main frequency determining element in the K3/K3S is the TCXO and not 
the SI-570.

Are you looking only at the native SI-570 thermal data, or are you 
finding from our measurements that the SI-570 in the new synth boards is 
not following the stability of the TCXO?  The SI-570 should slave off 
the frequency of the TCXO.

I do not know the rate of synchronization between the SI-570 and the 
TCXO, so I will have to leave that part of your question unanswered.  
Perhaps the engineer for the new synth boards will respond with 
definitive information.

73,
Don W3FPR

On 6/28/2016 10:09 PM, brian wrote:
> Please correct me if I am wrong.
>
> I believe the heart of the new synthesizer is a SI-570.
>
> Great phase noise but the output frequency is quite sensitive to 
> temperature changes.
>
> It has been observed that the corrections to bring the synthesizer in 
> step with the master oscillator happen over longer and longer periods 
> as the K3 warms up.  It never seems to reach a point of stability even 
> after 24 hours of warmup.
>