[Elecraft] [K3] Subtle Change in CW monitor tone

[Wes Stewart]

Could be short and long path at the same time.

Otherwise, you could be just hearing the harmonic distortion in the audio circuitry.  Not only is there third order stuff, which is regrettable but not unusual, but my K3 has second order distortion that is well... I won't go into that.

A few days ago, I drug a passive audio filter that I used in my early EME days out of storage and plugged it in to the K3 and the difference was amazing.

In those days, I preferred a 600 Hz beat note; as I've aged, I prefer a lower one, around 450 Hz, so I'm considering building one for the new frequency. 

Although the last thing my K3 needs is another dongle, passive filters have the advantage not requiring power and not (unless driven beyond belief) generating IMD.

(Speaking of EME and long and short path, I once was pointed at the setting moon looking for JA or UA0 when I heard a CQ.  Then I heard another CQ on a slightly different frequency.  It took a few moments to realize it was one station, W5UN.  I was hearing him on tropo (900 mile path) off the back of the antenna and via EME off the front. The difference in path length and the Doppler turned him into two stations.)

--- On Thu, 3/11/10, Phil Hystad <k7peh.wa at gmail.com> wrote:

> I am not sure how to describe this
> but I will do the best I can.  When
> listening to a single CW station I detect a slight tone
> frequency change
> from the sending station.  It almost sounds like some
> other very close by
> (within 100 Hz) station is also sending but such another
> station does not
> exist.  I thought at first it might be a slight
> variation due to the
> sender's frequency control but I have ruled that out as it
> occurs with a
> number of different stations.  I can hear this mostly
> (or, maybe only) when
> the signals are strong, S9 and beyond.
> 
> Does anyone else detect this or is it just me.  It is
> not really a bother
> now that I am used to it but it seems to occur only when
> there is a slight
> pause in the sending, such as break between words.
> 
> Comments?
> 
> 73, phil, K7PEH
>