[Elecraft] K2 and CW

[David Wilburn]

I have an 718 with the 250 Hz filter.  That filter locks down things 
quite well, but it also allows "blow by" with large nearby signals that 
make things difficult also. In the short time I have been a CW op, the 
skill that Ron mentions is just starting to get to me.  I have often 
been frustrated by other ops nearby.  That is part of what drove me to 
the K2, was the many choices of filters.

I agree with Scott, in the since, that I am seeking a way to make that 
last filter have more isolation capability without further attenuating 
the signal.  Now that I have a little bit better idea what is going on 
with Spectrogram, after I have all the pieces finished, I plan on making 
another pass with that while sending some tones through and seeing what 
kind of tweaking I can accomplish.

Scott, have you put your K2 through the Spectrogram alignments yet?  I 
was not terribly impressed with the filters after the default settings 
were installed, but I was amazed after (several tries) I gave the 
filters a good alignment with Spectrogram.

David Wilburn
dave.wilburn at verizon.net
K4DGW
K2 #5982


Ron D'Eau Claire wrote:
> I can't speak about the 718 or the Elecraft DSP, but in my experience such
> "brick wall" filtering creates far more problems than solutions. A huge
> amount of unwanted stuff is produced by signals on the sharp edges of such a
> filter that appear throughout the passband - much of it is that 'noise' you
> mention. 
> 
> I work 99% CW and my K2 is seldom set for less than 1.0 kHz bandwidth. My
> minimum is 0.4 kHz used only when I get a "loudmouth" shouting from almost
> on top of the signal I'm copying. That occasionally happens during a
> contest, but that's about it. 
> 
> I do have a skill that a great many experienced CW ops have that might be
> the difference. We can copy easily with several signals within the passband.
> It's like listening to one voice in a crowded party; we just "tune out" the
> other babble going on around us unless it's something we want to follow. It
> only gets difficult if one nut starts shouting in my ear when I'm trying to
> listen to someone else, Hi! 
> 
> Ron AC7AC
> 
> 
> 
> -----Original Message-----
> 
> Hello
> I haven't had my K2 (# 5846 ) long enought to fully understand all the
> different settings that are possible with it , so I have a question. My CW
> filter setting are FL-1 1.50, FL-2 0.70, FL-3 0.40, and 
> FL-4 is 0.10. Even FL-4 is no where near as effective as the 250 hz crystal
> filter in my Icom 718. When I turn on the 250 hz filter in the Icom, it's
> like building a wall right on each side of the signal that I am listening
> to. Nothing else is heard except noise and signals that are exactly on the
> same frequency. Is this kind of selectivity possible with the K2? If I
> installed the DSP option would that help? And if so, what would the filter
> settngs need to be? The only options I presently have are the 160 meter
> option, noise blanker, serial adapter, ssb option, and the KPA100. Thanks
> Scott N5SM
> 
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