[Elecraft] [K2] VFO alignment & display accuracy

[Don Wilhelm]

Sean,

If the BFO (TP2) is at 4913.05 and the VFO (TP1) is at 14912.97, then 
the frequency read at TP1 must come *up* in frequency by 9 to 10 Hz.
In other words, the count *must* rise.
 From what you said, the count will rise above 14912,97, and that is 
exactly what you want.
The count for the VFO will move about 5 times faster than the BFO, so 
try setting the count at TP1 at 14913.07 as your first guess, then check 
TP2 - it should be near 4913.07 - if not make minor adjustments until 
the 3 low order digits in both counter displays are the same when 
properly tuned to WWV.

On tuning to WWV, you must do that is SSB mode, and the carrier will be 
at zero frequency (which you cannot hear).  I recommend you use 
Spectrogram or other audio spectrum analyzer to show you the frequency 
of the tones transmitted by WWV.  The 1 second tone every minute is at 
1000 Hz, and the normal tones alternate between 500 and 600 Hz with a 
440 Hz tone 2 minutes after the hour.
Tune the VFO to align those tones at the correct frequency.

If you do not have Spectrogram, you can download it from my website 
www.w3fpr.com.

Note that after running CAL PLL and CAL FIL, the count frequencies will 
be different than they are now.

You might want to review the K2 Dial Calibration information on my 
website www.w3fpr.com.

73,
Don W3FPR

On 4/16/2014 1:18 PM, Sean Michael Johnston wrote:
> I have been trying to get my VFO aligned by adjusting C22 based on the methods recommended by N6KR and as posted in the app notes on the Elecraft website - http://www.elecraft.com/Apps/notes_on_adjusting_c22.htm.
> I can never get it closer than 70 Hz. I am using the 10MHz WWV signal for reference. When I switch between TP1 and TP2 the closest match I can reach is between 4913.05 and14912.97. I tried to adjust for a -70 Hz offset while connected to TP2, but 14912.97 is as far as the I can go before the count starts to rise again.
> I saw an older post where Don W3FPR mentioned changing C21 to a different value. Would this solve my issue, and if so, are there any suggestions as to which value I should use?
>