[Elecraft] K2 Alignment with Spectrogram

[Jim Faulkner]

Don,

Thanks a lot. It appears that I'm probably over-thinking this. I'm using
my n-gen for a source, and I can identify the skirts. I did as you
suggested with L-34, and then adjusted it again using my ears. With
Spectrogram, as I adjusted the height of the peak of the spike, the
noise on the signal did not ever change. Using my ears I could tell that
the noise was being reduced, so you're probably right about picking up
the noise between the rig and computer. 

L-34 is still maxed out. I wonder if that's a problem, and if there
would be more to be gained if there were more adjustment, or should I
just declare victory, and move on?

73, Jim KO5V

On Tue, 2011-05-03 at 13:32 -0400, Don Wilhelm wrote:
> 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