[Elecraft] K2 Alignment with Spectrogram

[Don Wilhelm]

  Jim,

You may be picking up noise on your soundcard input cable.
The only thing you really need to see are the skirts of the passband (so 
you can discern the center for CW and the proper placement of the low 
frequency skirt close to 300 Hz for the SSB filters) - most everything 
else can be ignored for the purpose of aligning the filters.  In other 
words, you are not analyzing all aspects of the audio signal, just 
determining where the passband is.  You should have only noise coming 
into the K2.  If there is a signal present, it will only confuse the 
display and make things more difficult.

For the L34 adjustment, tune to the birdie at 7000 kHz - turn the preamp 
on so it is more pronounced.
Use something close to a 700 Hz wide filter.  Then first adjust L34 so 
the signal spike goes up as far as possible - then tune around that 
point (about a turn either direction) while observing the high frequency 
end of the audio spectral display to see if you can reduce the noise 
level there without reducing the height of the signal spike.  If you do 
not observe any difference, leave L34 set at the peak for the spike.

That is all there is to it.

73,
Don W3FPR

On 5/3/2011 12:39 PM, Jim Faulkner wrote:
> My K2 S/N 5149 has been up and running well for about 5 years. I finally
> decided to check out the filter alignment using Spectrogram. I
> downloaded v.16, and am running it through Wine since I'm using Ubuntu
> as an operating system. I couldn't get the version on Tom's page to run
> this way, and right now, I don't have easy access to a Windows machine.
>
>