[Elecraft] DSP impressions

Sun Aug 10 13:33:00 2003

Andy:
  Thanks for your comments.  They roughly parallel my own reactions.  I 
would add that I don't find the DSP to be particularly good at pulling a 
thoroughly marginal signal out of the noise.  This doesn't surprise me, 
because you can't process something that isn't there in the first place. 
It is excellent at making a signal that's somewhat above the noise stand 
out.  And it is great at reducing qrm and reducing background noise.
   The slight click, occasionally, on key-down is not really a big problem 
to me.  I'm certainly not contemplating the double 1.5Meg resistor mod to 
alleviate it.  I did, however, find the abrupt return to the background 
noise on key-up to be annoying.  I have essentially removed this problem by 
setting the t-r time to .03 from my initial setting of .00.  It required 
.03 to tame the abrupt return  "crash."  This doesn't affect the qsk too 
much.  I tend to send in the mid thirties, and you can't hear between the 
dots anyway beyond, maybe, 20 wpm.  So, at 30 wpm, there isn't much 
practical difference between .00 and .03.  There may be better ways to 
adjust the performance of the DSP to the K2, but I suspect it's going to 
take the kind of input and design changes that only the likes of Wayne, 
Eric, and Lyle can put together.  So that's probably for the K3 sometime in 
the future.  Always nice to have something to look forward to, and 
meanwhile the DSP is quite some addition.

best wishes,

dave belsley, w1euy

--On Sunday, August 10, 2003 11:05 AM -0400 Andy Bullington 
<[email protected]> wrote:

> After using the KDSP2 for a couple weeks (CW only) these are my
> impressions.  I love the sound of the filters and the degree to which
> noise is softened or eliminated. They are easy to use and easy to listen
> to. When used in conjunction with the xtal filters, nearby QRM can be
> virtually eliminated. This is what I was hoping for when I bought the
> KDSP2 and I haven't been dissapointed.     For CW I don't personally like
> the NR function. The distortion added to the incoming CW signal is more
> bothersome than the noise it eliminates, for me. I have tried all
> possible settings of the NR with CW but I've settled on OFF.     The K2
> has close to perfect QSK and the slight scratchy quality from the DSP is
> at first annoying but it is really very slight and I've grown used to it.
> I realize there is a mod for it but it doesn't bother me enough to, at
> this point, take my new K2/100 apart and start messing around.    I DO
> wish there was a 1 button ON/Bypass function for the DSP. That would
> definitely be assigned to PF1 or PF2 if it were possible but it seems it
> is not. As it stands, its several button pushes to get to the On/Bypass
> function.    I still haven't gotten good at selecting the DSP filter I
> want. I invariably tap instead of hold at some point and end up having to
> cycle through all the xtal filters to get back to where I want to be.
> Bottom line is I like the KDSP2 very much and its a great addition to a
> great radio.                            Andy W1AWB
>
>
>
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----------------------------------
David A. Belsley
Professor of Economics