[Elecraft] k3:TX Monitor-some odd sound -beta?

[Bill W4ZV]

juergen piezo wrote:
> 
> Just noticed this when playing around with the K3's monitor.
> 
> With the Gate off
> EQ flat
> MH2 hand MIC
> TX test mode
> Band 7mhz
> 
> While whistling there is a odd artifact. If I whistle I get a sound that
> sounds  like a oscillator pulling in a receiver. I dont get any odd sounds
> with normal voice testing
> 
> .With a continuous whistle I get this artifact that  is a mirror of the
> whistle, however it seems to shift frequency or pull the louder you
> whistle.It might be a IMD  product? I have never noticed this before in
> the K3's monitor. I will also check the clubs K3's and report back.
> 
> Anyone else get this?
> 

Are you using headphones or the internal speaker?  If the latter, physical
microphonic modulation of the VCO can cause spur artifacts.  I've never
experienced this because I never use the speaker, but I've noticed it on CW
signals from other K3s.  The audible PITCH tone can modulate the VCO causing
spurs at +/- PITCH setting.  I suppose the same could happen in SSB if
MONITOR volume were high enough.

Elecraft has a stiffener/damper fix for the VCO board if this is the problem
you're having.

73,  Bill

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