[Elecraft] DSP for CW

[Andy Bullington]

Maybe this should come under the heading of stupid ham tricks.  Last summer
I got the KDSP unit and was ultimately disappointed. I set up the NR a dozen
different ways and ended up not using it because I didn't like the sound of
the CW note when it was set up strong enough to have an effect and when it
was at a mild setting it seemed to make a noisy band sound as if it was
coming out of a tunnel. All the NR experiments were done with the DSP in the
LOWPASS setting. On the other hand the xtal filters I already had seemed
more than enough for selectivity on a busy band and the DSP filters didn't
seem to add anything.
     I was actually on the verge of pulling it and selling it. Now I'm
really glad I did not. As the bands have gotten noisy with the advent of
warm weather I have been getting more and more fatigued listening. Well a
couple nights ago I inadvertently ended up on the second DSP filter and
noticed that the QRN was way down. And the NR was OFF!! A/B with the xtal
filter settings I found the DSP settings to be much quieter. I hadn't been
using them at all...I had just been using the xtal filters and remaining in
the LOWPASS DSP setting. Now I have a very light NR setting to go along with
the DSP filters and have jettisoned the LOWPASS setting in favor of an 800hz
setting for the first DSP filter and the difference is quite dramatic. The
CW notes sound great and background noise is radically reduced. Live and
learn.
                    Andy W1AWB