[Elecraft] Regarding the K3 and high QRN levels

[Edward R Cole]

My first experience with DSP was using my FT-847.  It is OK but not 
spectacular.  I mainly operate VHF+ and mostly eme so that is a 
different thing than HF.  The FT-847 is audio DSP so that limits it 
right away.  DSP filters are fixed in CW: 400-200-100-25 Hz.  NR 
worked OK on SSB.  NB was not worth turning on.

The K3 has IF DSP so a different animal.  I like the versatility but 
that means a steep learning curve to discover what works, when and 
where.  I am impressed with NR on HF SSB.  Having a combination of 
roofing filters and DSP filtering really works nice when digging out 
super weak signals.  The NB is pretty good on impulse noise (way 
better than the FT-847).

DSP technology is advancing quickly.  My hearing aids are 
digital.  They separate the audio spectrum into 22 channels and have 
echo cancellation and four NR routines including 
noise-cancellation.  So I guess I will always have DSP when listening 
to my K3 (or anything) ;-) .  As the sampling rate increases for DSP 
the closer it will be to analog hearing.  My hearing is -30dB so I 
must use hearing aids.  They are predicting in 10-15 years implant 
DSP on the audio nerve will render hearing loss completely cured...in 
fact those with it will hear better than natural hearing (ahh, bionic ears!).

This applies to radio DSP in the same fashion.

The K3 has versatility that I have not begun to use (and not just 
DSP).  I think as one gains experience in using DSP in more 
situations it will grow on you.

73, Ed - KL7UW

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Message: 18
Date: Thu, 08 Jul 2010 19:11:39 -0400
From: Don Wilhelm <w3fpr at embarqmail.com>
Subject: Re: [Elecraft] Regarding the K3 and high QRN levels
To: elecraft at mailman.qth.net
Message-ID: <4C365B2B.8020209 at embarqmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Tom,

I do agree that a specially tuned analog system will provide better
results for the specific task that it is tuned for than a digital system
any day.
The advantage of digital is that it can be made "almost as good" while
being more flexible through the use of computing power.
Your desires tend toward weak signal CW operation on the low bands - we
all know that.  But an analog system tuned to those needs would not be
ideal for ease of operation in say a ragchewing SSB situation - for one
thing the filters are too narrow :-) .
The major advantage offered by DSP is the ability to change the
filtering with the turn of a knob, and process the modulation and
demodulation tasks with computational algorithms rather than changing
the hardware - tailoring the algorithms to each task.  Is it as good as
analog tuned for a specific task?  NO - but it is usually better than a
general purpose analog system that attempts to be "everything to
everybody".  The equivalent flexibility with the same degree of
"best-ness" would be cost prohibitive if attempted in analog.

73,
Don W3FPR



73, Ed - KL7UW, WD2XSH/45
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