N2GZ identifies fatigue is an important issue. A sort of acoustical
psychosis sets in if you listen to a static crashy band with the same
narrow filter for hours at a time. One advantage of having multiple filters
available (either analog or DSP) is that you can switch between filters to
help relieve this psychosis.
What's very nice about modern DSP, is you can dial the bandwidth up and
down very nicely. Not that this was completely unavailable with passband
tuning in older analog rigs, but the best DSP filters default to a very
nice shape that can reduce the "ringing" that also leads to acoustical
psychosis.
Crystal filters with Gaussian shapes to reduce ringing have been available
for decades, but not generally used in ham equipment. The reason? They were
not "brick wall" filters with sharp shape factors - and crystal filter
shape factors have been used in ham radio marketing for a long time.
The best of the DSP equipment available today has CW filters that are
inspired by Gaussian filter shapes. The shape factors are not as impressive
but the resulting filter is far more useful for CW guys in crashy low bands.
Tim N3QE
On Tue, Aug 4, 2015 at 9:26 PM, Greg Zenger <n2gz@gregzenger.com> wrote:
> I suspect a well trained and practiced brain may be able to out perform a
> DSP assisted average brain... However over the course of a contest (24-48
> hours of [near] continuous operating) a DSP assisted average brain may
> have an advantage due reduced listening fatigue... Of course some DSP can
> positively contribute to listening fatigue and others negatively... Quality
> of DSP and operators ability to adjust are key factors here. This is a
> topic I follow closely, but can't think of any articles or studies off hand
> that would answer your question... A sold PhD thesis topic this would be.
>
> Greg N2GZ
> On Aug 4, 2015 9:02 PM, "Roger D Johnson" <n1rj@roadrunner.com> wrote:
>
> > Although I don't consider myself among the "highly-skilled and talented",
> > I
> > can't think of an instance where DSP made the difference between making
> > a contact or not. I do have an Autek QF-1A wired into the audio of the
> main
> > receiver of the K3 as the AudioPeakingFilter on the K3 is too sharp.
> >
> > 73, Roger N1RJ
> >
> >
> > On 8/4/2015 8:25 PM, Art Snapper wrote:
> >
> >> Mike,
> >>
> >> Are you referring to a specific modulation mode?
> >>
> >> How about adjacent channel interference issues?
> >>
> >> I like your question.
> >>
> >> Art
> >> ᐧ
> >>
> >> On Tue, Aug 4, 2015 at 7:39 PM, Mike Waters<mikewate@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
> >>>
> >>> _________________
> >> Topband Reflector Archives - http://www.contesting.com/_topband
> >>
> > _________________
> > Topband Reflector Archives - http://www.contesting.com/_topband
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
|