[Elecraft] REF CAL

[Paul Christensen]

>> Being able to lock my K3 to an external 10MHz reference might be nice
someday though.

> That might make it more stable but it won't make it more accurate.
>
> For the reason why, see: 
> http://n2.nabble.com/Ref-Osc-Cal-Method-4-td2595451.html#a2595451

Wes,

I read your description, but are you also implying that a 10 MHz GPSDO would 
not provide additional accuracy to the K3?   When a precision 10 MHz time 
base is used as a superhet receiver's frequency reference, the accuracy is 
generally not as good as the precision time base itself owing to decimation 
error, but it is still significantly better than an internal TCXO even when 
the best calibration methods are used.

For example, when a GPSDO is used with the Icom 7700, absolute accuracy does 
not approach the 1x10^-11 long-term accuracy of the GPSDO and can be off by 
~ 0.05 Hz at 1 MHz and probably rivals the real-world accuracy of its 
internal 0.05 ppm OCXO.  But the K3's optional TCXO is specified at 1.0 ppm 
accuracy.  So, if the K3 were combined with a GPSDO or a high-quality OCXO, 
I would expect much better accuracy and stability than that of the Elecraft 
TCXO.

Paul, W9AC