[Elecraft] K2 calibration questions

[Don Wilhelm]

John,

Certainly, this is a valid reflector for any Elecraft product.

Don't worry about exactly 4.000 MHz on that reference oscillator. It is 
only important that it be "right on" just before running CAL PLL 
followed by CAL FIL - and the frequency may not be exactly 4.000 MHz 
when set properly anyway.  That check in the manual was intended not as 
a calibration point, but only as a check to see if the oscillator was 
actually in close range of where it needs to be.
When not running CAL PLL and CAL FIL, the K2 does not depend on that 
oscillator at all, it uses the data stored in memory during those 
routines to know what frequency to display.

If you really want to fine tune the K2 dial calibration, go to the 
article on my website www.w3fpr.com and follow the procedure there. You 
will need to use Spectrogram or other audio spectrum analyzer to 
correctly tune in WWV and also to judge the width and placement of your 
IF filters.
If you need spectrogram, look for the links near the bottom of my Home 
webpage.  Those are links local to my website and those copies have been 
virus scanned many times and are known to be 'clean'.

Be aware that due to limitations in the BFO DAC, you may find up to a 
20Hz error in the final dial calibration results.  That was quite 
tolerable until recently when new data modes (such as JT65) were 
developed requiring greater frequency accuracy.  The K2 may not be 
suitable for those modes for that reason.

73,
Don W3FPR

On 8/23/2015 2:02 PM, John Wiener wrote:
> Hi
> Do people still ask about the venerable K2 on this group?  hi
>
> my K2  serial # 5312 :
>
> I built it 9 yrs ago now.
>
> SO, I went back and (nervously) re-opened my K2 and re-did some of the calibration routines.
>
> The 4 Mhz calibration would not zero beat at 4.0000 Mhz  but at 3999.8
>
> The PLL ref Bosc range was OK
>
> BFO test was OK
>
> The CAL FCTR procedure would not allow zero beat on WWV 10 Mhz sig.  Readings were zero beat at 10000.19.  Needed to get FCTR to 14911.82   could only get to 14912.08  a diff of 1.74
>
> Re-did PLL as required.  No probs there.
>
> I am aware of the limitations of freq calib with the K2 when in the Hz range   However I did not used to have this much of a problem.
>
> I am probably missing something obvious.
>
> That’s where you guys come in!
>
>