[Elecraft] K2 L34 tuning revisited

[Rick Shindley]

I retuned my K2's filters the other day.  I made the filter flattening mod,
PSK-31 mod, and used a noise source and the latest tuning advice from the
Elecraft web site.  I got to the part where L34 had to be adjusted for
lowest noise and maximum signal while listening to the birdie at 7 MHz.  I
built the rig a year ago and anxiously moved through the adjustment
procedure. L34 was tough to set, but I forgot about it and moved on.  This
time I wanted to be very careful and deliberate.  ARRRRGGGH!!!

I could not discern a point on L34 where the signal was more pronounced
relative to the noise. I finally used Spectrogram to display the audio
signal and found that no matter where I set the coil slug, the relative
difference between the noise and the audio peak remained the same. (The
manual indicates to adjust for max sig/noise.) I ended up peaking the slug
where the audio peaked without regard to the noise level, since it made no
difference. The slug ended up about one turn down from the top (not near the
bottom where my ears believed it belonged).

I wonder if others see a relative change between signal and noise while
adjusting L34 using spectrogram?

Rick
KC0OV - K2 1360