Topband: Which is best for copying the weakest DX - DSP or the ear-brain combo?

Jeff Kinzli N6GQ jeff at n6gq.com
Wed Aug 5 21:00:58 EDT 2015


So, this isn't a scientific test, but a number of years ago (pre-K3) I
built an Elecraft K2 (great fun to build) and then built the DSP board
for it as well.

As a relatively experienced ear, and always (due to other hobbies)
listening in the noise, I found the K2+DSP to be unmatched in terms of
being able to pull a signal out of the noise. Thing is, I didn't have
a chance to do any A/B testing except against an old TS830S, and the
difference was certainly there, but never tested this against any
"modern" or "good" radios.

The combination of the very quiet receiver, and the DSP with the right
configuration was quite amazing - there could be a very very weak
signal there that only at times you could even tell there was
*anything* in the noise, and switch in the DSP and the signal came up
out of the noise and was copyable. This happened time and again, and
of course some times were much better than others, but it struck me at
the time that this was a game changer in terms of weak signal DXing,
and maybe contesting if conditions were favorable.

I since sold the K2/DSP and replaced it with the K3 but since that's
an all-SDR/DSP radio the on/off difference isn't apparent.

This was on CW, BTW. I never built the SSB side of the K2 :)

I still miss that little K2, it was a joy to operate and especially
listen to. When things got tough, the DSP made it possible to pull out
and work stuff I would have never been able to hear or work otherwise.

73 de N6GQ

On Tue, Aug 4, 2015 at 4:39 PM, Mike Waters <mikewate at gmail.com> wrote:
> I'd like to know whether it's ever been established that some very talented
> hams can out-hear the best SDRs and/or DSP available. Can a skilled
> ear-brain combo (such as some highly-skilled and talented 160 meter
> contesters) beat state-of-the art digital signal processing when it comes
> to copying the very weakest of signals buried in the noise?
>
> I always thought Linrad was the best DSP software, though I never got it
> working right here (older sound card issues in Xubuntu).
>
> I asked the following question at
> http://www.eham.net/ehamforum/smf/index.php?topic=104388.msg861047#msg861047
> : "Are there any people who can hear weak signals with a good analog
> receiver, who --if they could instantly switch their antenna and headphones
> from the analog RX over to the best SDR made today-- simply couldn't hear
> any better with today's best SDRs and/or DSP software?"
>
> There's been a few opinions, but how about multiple valid tests?
>
> 73, Mike
> www.w0btu.com
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband


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