[Elecraft] [k3] NB & Chirp

[Wes Stewart]

One of my first transmitters was a Millen with a keyed 6L6 crystal oscillator and an 807 final.  So I know what chirp sounds like.  

It sounded like chirp to me.

Wes

--- On Mon, 12/7/09, Vic K2VCO <vic at rakefet.com> wrote:

> From: Vic K2VCO <vic at rakefet.com>
> Subject: Re: [Elecraft] [k3] NB & Chirp
> To: "Wes Stewart" <n7ws at yahoo.com>
> Cc: "Elecraft Reflector" <elecraft at mailman.qth.net>
> Date: Monday, December 7, 2009, 11:26 PM
> Wes Stewart wrote:
> > I worked and have since been listening to J79WE on 40m
> CW for some time.  The wind is
> > blowing about 40 mph so the power lines are acting up
> and I've been tweaking the noise
> > blanker.
> > 
> > While playing around I noted that his signal had
> developed some chirp.  I thought that
> > strange, since he was clean when I worked him.  I
> fired up old reliable, my TS870 and
> > listened to him and he was T9 with no chirp (and no
> audio distortion).  On the K3 he
> > definitely had chirp, then I happened to turn off the
> noise blanker and the chirp went
> > away.
> > 
> > The Noise blanker setting were IF=MED4 and
> DSP=T3-7.  The chirp seems to be related to
> > the DSP part of it.
> > 
> > Anyone else notice this?
> 
> Are you sure it was chirp -- a change in frequency when
> keying? Or was it a softening of the leading edge of the
> keyed elements?
> 
> The latter is characteristic of the DSP noise blanker when
> it's at an advanced setting, like T3-7. Some distortion is
> part of the tradeoff for noise blanking.
> 
> I used to say "you know, it sounds like a guy with a
> slow-starting crystal oscillator" until I realized that you
> very rarely hear any crystal-controlled rigs these days.
> -- 73,
> Vic, K2VCO
> Fresno CA
> http://www.qsl.net/k2vco
>