[Elecraft] KDSP2 verses KAF2?

[James Hammons]

I find that the KDSP2 bandwidth and notch have little negative
artifacts.  They are so good that you don't mind leaving them on in
almost any situation.  The noise reduction is very clean on CW and
makes the copy more pleasant on many situations.

The noise reduction in SSB does have some negative affects on the
sound of strong signals where you don't really need it for copy,
Where it really shines is on poor signals it can make the difference
between copy and no copy.

I find that tuning in a SSB station is difficult with the noise
reduction on.  I tune it for best sound with the noise reduction off
and then if needed I turn it on. =20

On the KAF2 the real time clock is somewhat useful because of it's
presence in the display rotation.  On the KDSP2 it is almost useless
for me because it is difficult to access.  On both modules they have
kept time as well as a good watch.

On digital modes either module is of little use for me.  Noise
reduction is not available in the rtty mode on the KDSP2 but I find
that on the SSB mode it does not seem to cause any problem with the
copy of PSK31.  The various bandwidth and noise reduction don't seem
to make any difference to the computers copy.  I have my crystal
filters on rtty set up to center on 1.5khz I find that the crystal
filter at narrow 100hz makes for the best copy, I center the station
on 1.5khz using the wide filter then if I need it I narrow down the
bandwith. With careful setup of the Cal Fil, the stations only move
about 10hz which does not cause a problem.  I think this is because
the problem affects the AGC and the AGC only sees the crystal filters.

I much prefer the KDSP2.  It's only negatives for me are the higher
cost and the slightly higher current draw when on the battery, but you
can always turn it off.

James AI4CQ