[Elecraft] Frequency Anomaly -- Tamed

[Mike Harris]

Remember that what you have set is a fixed number representing the TCXO 
frequency that is correct only at the time you adjusted it. The reason 
being is that the TCXO frequency drifts. Mine will move +48Hz from a 
cold start to plus four hours. Thereafter is hardly moves. This drift 
will result in the display frequency and the true frequency diverging.

In my unit I have concluded that setting REF CAL after about an hours 
warm up is a reasonable compromise. However, I guess not all TCXOs will 
drift the same way or at the same rate.

The biggest driver is likely front panel temperature because the TXCO is 
located within that environment. My K3 front panel is pretty loaded with 
the sub RX dsp board and the DVK. It increases from +24C at switch on 
and reaches +39C after a couple of hours. This is easily recorded and 
from that you can judge what would be a suitable warm up period before 
doing the Method 2 calibration.

All this was determined when I started using a 10MHz GPS disciplined 
reference and the K3 REF LOCK option.

Regards,

Mike VP8NO

On 19/01/2019 22:36, Richard wrote:
> To all who jumped in to help — thanks.
> 
> I just performed Method 2 as found on page 53 of the K3s Owner's Manual, and it made a huge difference all around. Wish I could paste it here.
> 
> Cheers!
> Richard Kunc — W4KBX