[Elecraft] K2 CAL PLL confusion

[W3FPR]

Mark,

That Elecraft document saying to run CAL PLL on each band is very old. 
CAL PLL is only run on 40 meters with the MCU version 2.0 or above (it 
was changed a long time ago).

To adjust C22, tune to 10 MHz WWV (even if the dial is off), and since 
you have Spectrogram there, tune so the audio in SSB shows the tones 
correctly - they alternate between 500 and 600 Hz with a few exceptions.
That is only the start.  See the article on my website www.w3fpr.com for 
the full procedure(s).

Once you have C22 adjusted correctly, run CAL PLL and then run CAL FIL 
on each filter (because the old stored frequencies will have changed) - 
even if the filters still seem right, you must run CAL FIL changing the 
setting and then changing it back to force storing the new frequency.

73,
Don W3FPR

On 1/5/2026 9:46 AM, Mark Volstad via Elecraft wrote:
> I'm struggling to resolve a frequency error of nearly 7 kHz on my
> newly constructed K2, s/n 8115. I'm using my K4 as a frequency
> reference -- it is accurate to within a few Hz of WWV.
> I found a document called "Adjusting C22 to put the K2 on Frequency"
> in the Builders Resources section on the Elecraft web site. It states
> that CAL PLL must be run on *each band*, but when I attempt to do so
> on any band other than 40m, I get an INFO 232 error. Is the document
> wrong?
>