[Elecraft] [K3] Elecraft

[pd0psb]

Evert,

There's a small LPF board in betatest phase which cuts off anything above
K3's passband.
May be you can ask Elecraft to test a sample.
Especially people with good hearing (congrats, you are an exeption nowadays
:-) can benefit form this board. It's a 24db/oct chebychev with low noise
opamp that doesnt have any coloration in-passband.

As a quick solution you could also try 2 elco's over the HP outputs, I tried
4,7 or 10uF.
This will give a 6db/oct roll off.

I've read the LPF filterboard might become generally available someday for
people wishing to clear the above-passband products.

73'
Paul
PD0PSB



Evert Bakker (PA2KW) wrote:
> 
> Hi Tom,
> 
> --- Good headphones designed for communications shouldn't even go that
> high. ---
> 
> May be you are (should be) correct. But my Heil Pro does as I do hear
> these
> high tones coming through.
> 
> Just an example; when using SSB (MON =2) 30% of the time I clearly hear a
> "tune" of high frequency (must be somewhere around 16 Kc if I compare it
> with the line transformers in old TV sets) when in TX mode. It looks like
> a
> lottery when pushing the PTT, it's there or not.
> 
> In an earlier message (must be months ago) I stated that I do hear high
> frequency components on each signal (SSB and CW) which is above S3 and
> they
> are related to the signals received.
> The high component which I'm talking about can't be influenced (volume and
> tone) by the RX-EQ so it looks like an uncontrolled side-effect.
> 
> So my conclusion;
> It's either coming from the K3 and totally independent from the headphones
> used, or it's the combination K3 - Heil Pro set, or it's an oscillation
> between my ears initiated by lids on the band (don't take the last one to
> serious).
> 
> (un)fortunately most hams can't hear above 10 Kc if we look at the average
> age and the given statistics. So they won't notice these artifacts.
> 
> Yes I do have an old headphone (no mic included) from Telex which doesn't
> produce or show this effect. Either the combi K3 - Telex doesn't generate
> the high frequency components or the Telex isn't able to make it audible.
> 
> With this knowledge, and your question about the Heil I can do two things:
> Say nothing or warn you just in case you are able to hear above 10 Kc.
> 
> 
> BTW
> Let me be clear, I do have 2 K3's, (SN0812 & SN2185, both have the same
> issue) but I'm still very happy with them! Receiver performance and audio
> are the most important points for me, not the bells and the whistles. I
> hope
> this audio issue will be solved once and the K3 will be perfect (for me).
> Some issues will be solved, some never. Nothing is perfect, but the K3
> comes
> close. 
> 
> Do whatever you like with this information, it is just my experience and
> opinion
> 
> 73's, Evert PA2KW
> 
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