[Elecraft] k2 receiver shift problem fixed, now tx shift problem

[Don Wilhelm]

Luca,

1.2 kHz off means that you have one or more of the CW filters set on the 
wrong sideband.

The CW BFO frequencies should all be in the range of 4913.xx kHz.
The CW r BFO frequencies should all be higher than 4914 kHz.

Go to CAL FIL and tap BAND- to display the DAC value for the selected 
BFO.  Use FL2 first with a width set near 0.70.
Now, use Spectrogram (or Spectran or other FFT audio spectrum analyzer) 
and move the VFO knob to center the filter passband at 600 Hz.  Move the 
passband around and you will see that there are two points where the 
passband will center at 600 Hz.  For CW use the setting with the lower 
DAC value and for CWr, use the setting with the higher DAC value.

Do that for all the CW and CWr filters FL2 through FL4.

Now do FL1 - If you have FL1 set to a width that is greater than 2 times 
your sidetone pitch of 600 Hz, then you cannot center the filter and 
retain single signal reception.  You must position the filter passband 
so the left edge of the passband slope is at a low audio frequency, but 
make certain the slope can be seen clearly and drops in amplitude at the 
left edge.  For CW use, it does not matter what low audio frequency the 
slope is positioned at, but it does matter that the filter skirt drops 
to near the receiver noise level above zero frequency.  Again, there are 
two DAC values where that can happen - use the lower one for CW and the 
higher one for CWr.

If you have followed that, you should transmit on the same frequency you 
are receiving.
It is possible that we have a language confusion problem at work here 
too.  If I have not been clear enough, please send me an email and I 
will try to help more.  Sorry that I am unable to communicate in your 
native language.

73,
Don W3FPR

luca amendola wrote:
> Hi
> Don the problem was again in the bfo.
> I re-did again cal fil using the tom's procedure.
> I tuned bfos with the graph spectrum.
> Finally the bfo is shifted exatly of 1.2 khz.
> the same values of cw nor bfo applied to cw rec cal , produce a perfect 
> centered filters in cw rev!
> what does it mean?
> luca
>   
>