This being catch 22 is true to a limited point, but it
has more to do with the evolution of technology. These
issues of DSP and other digital artifacts are akin to
the transition from tube receivers to solid state. Did
solid state technology improve receivers? Absolutely,
were there some undesirable side effects, especially
for the first couple generations, of course. Once the
undesirable side effects were recognized the various
companies proceeded to correct them, and they have,
virtually all solid state receivers today dramatically
exceed tube receivers in just about every respect. I
see DSP and software defined radios (SDR) of today
being like the circa 1970 solid state receiver
technology, clearly the future direction of radio
design, but also has room for improvement and
tremendous technological advancement.
There really is no point in building software radios
that will only do what the previous, often simpler
designs already do quite well. What DSP and SDR can
give us are new capabilities that were simply not
possible before.
As write this, I have the two Peg's listening and
watching the excellent opening on 6M, by using a DEM
50-28 transverter and N4PY?s software in dual Pegasus
mode. I have one of them actually listening to a
particular signal and the other sweeping the band from
50.075 to 50.225. So every 4 seconds or so I get a
nice visual snapshot of a 150KHz chunk of spectrum,
continuously.
Operationally I can be listening to a signal on say
50.155, and then perhaps see a new "spike" on 50.198,
"Hmmm gee, I wonder who that might be", one click of
the mouse on the sweep display, and I'm instantly
there. Can a traditional radio design do that? Nope.
Thanks to the excellent work by Carl, N4PY and the
truly computer controllable Pegasus's this is now
possible, and all of this capability without a lot of
end user work or a huge investment. Currently there
are no other radios in the amateur market that can do
this (with proper control software development the
Kachina should be able to do this as well). And the
best part is that even better fun things can be done
by anyone with programming skills and ambition (I'm
definitely not a programmer, won't comment on
ambition). I'd really hate to see Ten Tec lose this
competitive edge they now have.
That is why it is important to not let the seemingly
little peculiarities of the new technologies go on
without some feedback to the manufacturers from us end
users in the field. But it is also important for us
customers to actually reward companies that do
incorporate the true "future of radio", not just bells
and whistles, by buying it. If we only buy the same
old radio concept, they will continue to only build
the same old thing, and then one day somebody else
will (build the new technology) and they will go out
of business. Just look at what companies are around
today that didn't exist in the early to mid 60's, and
who was around then and are gone today, and why?
Duane
N9DG
--- Bob & Linda McGraw K4TAX <RMcGraw@InfoAve.Net>
wrote:
>
> Al:
>
> You are absolutely correct. I wish the other folks
> understood this
> fact.
>
> 73
> Bob K4TAX
>
> LORONAAL A-USAex3 wrote:
> >
> > Hi, Everybody,
> >
> > An interesting discussion. Practically, I can
> understand those who say they
> > don't care about a spurious tone in the audio
> output that is so far down
> > that it cannot interfere with normal
> communications. Practically, that's
> > absolutely true. Virtually all radios have
> by-products, birdies, audio
> > intermod, phase noise, and other junk if you look
> closely enough. On the
> > other hand, Larry (VA3LK) is perfectly right to
> say that, for his extreme
> > weak-signal work, the distortion can't be
> tolerated. In the worst case I
> > suppose it would fool his decoding software into
> thinking that there were a
> > very weak signal there, when there really weren't!
> And that would be bad.
> >
> > What an interesting test, to put a spectrum
> analyzer on the audio output and
> > show the result in the product reviews. I'd like
> to see that.
> >
> > R,
> >
> > Al W6LX
> >
> > -----Original Message-----
> > From: Jim Cox [mailto:jcox@digitalexp.com]
> > Sent: Wednesday, June 27, 2001 6:54 AM
> > To: Duane Grotophorst; dslosty;
> tentec@contesting.com
> > Subject: Re: [TenTec] ARRL product review test
> change
> >
> > If you have to turn the volume up 100 percent to
> hear it, why worry about
> > it? How many of us run our radios at 100 percent
> volume?
> > I bet if you ran your car at 100 percent you'll
> hear some strange noises
> > too.
> >
> > ----- Original Message -----
> > From: Duane Grotophorst <n9dg@yahoo.com>
> > To: dslosty <dslosty@pipeline.com>;
> <tentec@contesting.com>
> > Sent: Tuesday, June 26, 2001 10:44 PM
> > Subject: Re: [TenTec] ARRL product review test
> change
> >
> > >
> > >
> > > I would like to see the ARRL add a product
> review test
> > > where they show the audio output spectrum of the
> RX
> > > audio passband with a 50-ohm load on the RX
> input.
> > >
> > > With today's digitally based radios (DSP IF or
> > > otherwise) there is a potential for, and
> frequently
> > > is, extraneous noises and other artifacts in the
> RX
> > > audio signal.
> > >
> > > At the risk of re-opening old heated debates
> here on
> > > the reflector, I have also seen the persistent
> tone in
> > > the middle of the RX filter passband the Larry,
> VA3LK
> > > saw with the Pegasus. It is actually quite easy
> to
> > > see, I used SR5 Spectrum Analyzer program (from
> > > www.ar5.com) to look at the audio passband. I
> can also
> > > see it on the waterfall display of the PSK31
> program I
> > > use. In fact both of the Peg's I have exhibit
> the
> > > exact same behavior. That tone is actually
> audible if
> > > you crank up the volume 100%. For what its worth
> > > though, the fact that you can turn the volume up
> all
> > > the way and not be driven out of the room by
> white
> > > noise is a testament to what Ten Tec has done
> well
> > > with their RX design.
> > >
> > > Anyone who is already wired up to do PSK31 or
> any of
> > > the other "sound card" modes, can simply
> download any
> > > number of freeware spectrum analyzers and look
> at the
> > > audio signal of you RX. I've used both SR5 and
> > > Spectrogram for my tests; I'm sure there are
> others.
> > >
> > > I haven't turned the audio spectrum analyzer
> loose on
> > > my other radios yet, but I do expect to find
> some
> > > interesting things. Bottom line is that whatever
> > > internally generated noises or other artifacts
> that
> > > may appear in the RX audio passband are actually
> every
> > > bit as important as all of the dynamic range and
> phase
> > > noise measurements that product reviewers are so
> > > focused on.
> > >
> > > 73,
> > > Duane
> > > N9DG
> > >
> > > --- dslosty <dslosty@pipeline.com> wrote:
> > > >
> > > >
> > > >
> > > > I don't know if this has been mentioned on the
> > > > reflector but I
> > > > found the changes announced in July's QST
> > > > interesting.
> > > >
> > > > The League is now going to use a 5KHz standard
> > > > spacing versus the
> > > > former 20 KHz spacing while testing receiver
> dynamic
> > > > range
> > > > and intercept points. This should better
> > > > characterize crowded band conditions.
> > > >
> > > > On page 80 of July's QST is a listing of
> several
> > > > current HF
> > > > transceivers. According to the new tests, the
> > > > Elecraft K2 and
> > > > the Ten-Tec Omni 6+ have far better figures
> than the
> > > >
> > > > IC-756PRO, FT-1000MP, etc.
> > > >
> > > > Of course, most of us already knew this.....
> > > >
> > > >
> > > > 73,
> > > > Doug/WA1TUT
> > > >
> > > >
> > > > --
> > > > FAQ on WWW:
> > > > http://www.contesting.com/FAQ/tentec
> > > > Submissions:
> tentec@contesting.com
> > > > Administrative requests:
> > > > tentec-REQUEST@contesting.com
> > > > Problems:
> > > > owner-tentec@contesting.com
> > > >
> > >
> > >
> > >
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> > > --
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> > >
> >
> > --
>
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