[Elecraft] (no subject)

[Don Wilhelm]

Dick,

I think you will find that setting the BFOs for the OP1 filter using a
wideband noise generator and a visual display of the audio output (like
Spectrogram) will produce much better results thatn the beginning settings
stated in the KSB2 manual.  The settings in the manual are adequate to get
one operational, but are by no means optimum.

Check the Dial Calibration article on my website www.qsl.net/w3fpr for more
information - Step 3 is the section on the CAL FIL procedure.

In answer to your question - yes, I understand the curiosity of the
electronics tinkerer.  The TUF-1 mixer is a higher level than the SBL-1, so
one could say that it already is a high level mixer - whether going to an
even higher level mixer type (and playing with the LO injection to get it
optimum) would yield a significant improvement or not is anyone's guess.  I
suspect that it would not yield enough improvement for Elecraft to adopt it
given the cost of the higher current drain, but improvement gain may be
worthwhile for some individuals.  Why not try it and let us all know the
results.

73,
Don W3FPR
----- Original Message ----- 
>
> I have fully completed K2 number 3892 now. I am mainly CW-op, so I kept
the
> SSB-option for the last...
> I have one problem though and a question.
>
> Problem: In SSB the course adjustment of the "carrier nulling" runs fine.
> But in normal SSB mode, I get audio but almost no output and a strong
> carrier which I can not "null" out. And yes, I did remove C167 ;)
> I also adjusted the carrier in respect to the x-tal filter according to
the
> instructions. I will keep on searching, but any help is appreaciated.
>
> Question: I wondered earlier why the K2 has no high level mixer, like
TUF-1H
> or TUF-3H. I found a TUF-1LH (10 dBm type) in my "stock"  now and wonder
if
> using that one further would improve IMD. I know, the K2's performance is
> allready stunning, but you know the way experimental radio goes about...
> It would require higher LO and therefore I thought that the feedback
> resistor of the LT1252 LO-driver would be doubled to lets say 1k. It will
> drain more current, but that can not be excessive I suppose.
> My question is if it will be worthwhile? And I do not find IIP3-specs on
the
> internet for the TUF-1LH, anyone knows?
>