[Elecraft] K2 dial alignment

[David Wilburn]

I like to use Spectrogram, and setup markers for 500 & 600 Hz, these are
the tones most often heard on WWV, and then use that to zero beat WWV.
With that setup I was able to get down to where I was 9.997 or 8 for the
10 Khz WWV signal.
-  

David Wilburn
k4dgw at k4dgw.com
K4DGW
K2 S/N 5982


On Sun, 2007-12-02 at 19:04 -0600, paul wrote:
> Hi,
> 
> Recently I started to upgrade my K2 (sn 2592) with the KPA100 kit.  Before 
> I could complete the KPA100 though, I had to upgrade the K2 from rev A to 
> rev B.  I have completed all the revs except for the firmware upgrade - 
> Elecraft sent only the MCU but not the IOC.  It is now being mailed.
> 
> Before the rev, the frequency on the dial matched the received frequency.  
> Now WWV is received on 10.012 MHz.  I have done the calibration of the 4MHz 
> several times - checking with a known good receiver (AOR AR7030+).  I can 
> vary the c22 and zero beat exactly on frequency (USB and LSB) - also at 
> higher harmonics (16Mhz).  I ran an antenna wire next to the 4MHz xtal and 
> listen on the SW receiver.
> 
> After the 4MHz calibration, I have run the CAL PLL and then modified every 
> CAL FIL entry afterwards.   Still no change.  The dial reads 7.010Mhz when 
> hearing 7MHZ and 14.020Mhz when hearing 14Mhz.
> 
> Otherwise, the receiver is excellent - much better than before.  Had a low 
> volume problem before, now it is really loud.  Did all the RF and contol 
> board changes, BFO temp stability mod, PLL upgrade, AF gain smoothness, 
> VFO ALC 10/12 meter band pass filter, AGC threshold (R1 from 51k to 
> 22.5k).  I have checked for bad solder joints or bridges - nothing wrong 
> that I can see.
> 
> I did not do the second crystal filer flatness mod or the sidetone mod 
> yet.  Also no firmware had been changed yet.  Any ideas what to check?
> 
> Thanks,
> 
> Paul
> AD5IW
> 
> Here are some measurements when receiving 10MHz WWV: 
> 
> TP3  14913.05
> TP2   4913.19
> TP1  12089.38
> 
> Dial: 10011.99
> 
> -------------------Range measurements
> PLL
> min: 12083.69
> max: 12094.29
> range:  10.60
> 
> TP3
> min: 14906.04
> max: 14919.09
> range:  13.05
> 
> BFO 
> min:  4916.99
> max:  4912.59
> range:   4.40
> 
> R30:  4.34V 10MHz
>       5.70V @ 4MHZ
>       2.02V @ 3.5Mhz
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