[Elecraft] KAF2 or KDSP2 for K2 #5287

[Vic K2VCO]

Alexander Ponomarenko wrote:
> 
> I have the question. How much better working KDSP2?
> It has very expensive price. Are the KDSP2 really so good
> working that I have to pay "half K2 price"?

I have both of them.  Keep in mind that I am only a CW operator, so you 
will have to get the opinion of an SSB guy if you want to know about 
that!  The KAF2 does nothing for SSB, while the DSP provides filtering 
and hetrodyne removal.

The DSP has the advantage of including a noise-reduction function.  It 
does not make it possible to copy a station that you can't copy without 
it, but it does make it more comfortable to copy a station that is close 
to the noise level.  The DSP has more flexibility in selecting 
bandwidths and better shape characteristics than the KAF2.  In practical 
terms, though, I don't think this translates into the ability to work 
stations that you could not work with the KAF2.

One DSP problem is that the noise reduction, if you use it, distorts the 
leading edge of a weak signal which degrades copy.  You need to back off 
the aggressiveness of the function to avoid this, which makes it less 
effective.

A negative factor, at least in my case, is that the QSK is not as clean 
with the DSP installed.  I've spent some time trying to clean up clicks 
(only in the receiver, not transmitted) that are related to the delay 
introduced by the DSP.  I haven't succeeded.

Recently, I took out the DSP and put back the KAF2.  After getting used 
to missing the noise reduction, I found that I prefer the KAF2.
-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco