[Elecraft] K3 QSK artefact

[Vic K2VCO]

David Cutter wrote:
> This is a re-post to see if it attracts comment.
> 
> This concerns an audible artefact using QSK cw mode.  When either rf
> gain or af gain are at maximum, there is an additional noise which
> accompanies the Morse characters.  

I've noticed the phenomenon that you describe, but it's not exactly an 
artifact. Looking at the audio output with a scope shows an absolutely 
clean transition between noise and sidetone, or, if the sidetone is 
turned down all the way, between noise and silence.

As the sidetone gets louder with respect to the noise, which occurs when 
you turn the sidetone level up or the audio or RF gain down, you hear 
less 'artifact'.

What I think it is is sort of an auditory illusion caused by the rapidly 
pulsing noise, and maybe the sharp rise/fall times of the noise pulses 
in between keyed elements (not the sidetone, which is shaped nicely).

I've suggested to Wayne and Lyle that they look at the way they ramp the 
gain up and down in QSK, and Wayne has discussed the possibility of 
making the tone quality of the sidetone user-modifiable. Maybe they will 
look at this when they are done with more urgent matters.

In the meantime, if it bothers you, just change the balance between the 
signal audio and the sidetone.
-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco