Duane,
Oh yes indeed there are. I've used many forms of Digital Signal Processing
in my earlier work, other than for noise reduction. I am though limiting
the discussion HERE to noise reduction, because that is the application of
interest to this particular group. In common with all forms of DSP that I
have worked with however, the DSP processor was always a dedicated,
specialized processor. Otherwise, the amount of "general purpose"
processing that would be required to accomplish the same effects would, as
one poster noted correctly, be overwhelming.
Another poster noted that the Orion manual makes reference to the automatic
NR function "having the same effect as a very narrow band pass filter".
Well yes, but having the same effect does not mean that it does it exactly
in that way.
Likewise, the phrase "building a filter around the signal" which has been
used in several posts in various forms does not mean that there is an actual
pass band being established. I've seen that language used elsewhere as a
simplified explanation of DSP, referencing the more familiar analog of a
filter, instead of trying to explain the math, etc, of true DSP noise
reduction.
Thus, while it might be the case that it simply builds a narrow pass band
around the signal, I don't think the phrases used thus far establish
conclusively that this is the case. It may be.
I'd like to know definitively, from Ten Tec. I am sure we all would.
73 de Gary, AA2IZ
----- Original Message -----
From: "Duane Calvin" <ac5aa1@gmail.com>
To: "'Discussion of Ten-Tec Equipment'" <tentec@contesting.com>
Sent: Friday, December 08, 2006 12:53 AM
Subject: Re: [TenTec] Noise Reduction Setting
> Gary,
> Your use of the term "DSP" almost sounds like you're limiting its
> definition to noise reduction only. There are many more applications of
DSP
> than just noise reduction.
>
> 73, Duane
>
> Duane Calvin, AC5AA
> Austin, Texas
> www.ac5aa.com
>
>
> -----Original Message-----
> From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com]
> On Behalf Of Gary Hoffman
> Sent: Thursday, December 07, 2006 11:36 PM
> To: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] Noise Reduction Setting
>
> Ok Grant....
>
> I'm not trying to split hairs with you or be blindly
> argumentative....however, a DSP processor does nothing else, by the
> definition of the term. If it is a general purpose processor, capable of
> doing "something else" then by definition, it is not a DSP processor,
which
> is not capable (in general) of doing something else, and in practice, is
not
> used to do something else.
>
> Now we come down to the crux of the matter. If the "DSP" processor(s) in
> the Orion are used to do general purpose processing, in addition to any
> "real" DSP processing, then I'd not call them actual DSP processors at
all.
> And then I would have to agree that there are likely nowhere near enough
> processing cycles available to do the type of processing I'm talking
about,
> in near real time.
>
> What I don't know is if this is in fact a correct statement of the facts.
>
> I was told, at the Hamfest at Ten Tec where the radio was introduced and
> which I attended, in person, by Doug, that there was true DSP noise
> reduction. I was very impressed, and pressed the point as to whether this
> was true. I was told yes. I was shown the "lab rat" radio....and the DSP
> processor was pointed out to me, physically.
>
> Now, I will admit that (at least) 3 things were possible:
>
> 1. They did not understand my question in the way I meant it.
>
> 2. I did not understand their answer in the way they meant it.
>
> 3. Something has changed since then.
>
> Would it not be nice if Ten Tec could comment ??????????? Please ???
>
> As far as "some kind of LMS algorithm".....I never heard of that in the
> sense of true DSP. I would guess that LMS means "Least Mean Square" which
> is a computation found in endless kinds of apparatus and data reduction,
but
> has, in general, nothing specific to do with SAW processors nor with
> subtraction of uncorrelated noise data from a larger data set. I don't
even
> know why it would be used...unless it just refers to a general "smoothing"
> of the signal, which might tend to blur out noise spikes ? I'm guessing
> there. I would imagine such blurring would also smear out the desired
> signal to some extent, which may be why people tend not to like it. Yet
> others do !
>
> Alas, what is the poor DSP signal analyst to do when faced with such
> questions :)
>
> Bottom line....I know the kind of signal processing I've been talking
about
> can be done in a very small space with small chips (but at a relatively
high
> price). I've seen this. I was led to believe that a low frequency
version
> of this was done in the Orion. The low frequency made it affordable. Now
> I'm told, more or less, the opposite.
>
> I don't know the facts well enough, and I'd sure like Ten Tec to offer an
> informed view.
>
> 73 de Gary, AA2IZ
>
>
> ----- Original Message -----
> From: "Grant Youngman" <nq5t@tx.rr.com>
> To: "'Discussion of Ten-Tec Equipment'" <tentec@contesting.com>
> Sent: Friday, December 08, 2006 12:01 AM
> Subject: Re: [TenTec] Noise Reduction Setting
>
>
> >
> > > Now, on the other hand, the kind of processing I've been
> > > talking about (and was led to believe is being done by Ten
> > > Tec...but who knows, maybe not) does not take huge parallel
> > > processors nor does it involve latency of any serious amount.
> > > In the military applications for example, SAW processors
> > > (Surface Acoustic Wave) handle this nicely, as do various
> > > hard wired ASICS. The latter are comparatively cheap.
> > > Neither do much actual processing, as the algorithm is pretty
> > > much hard wired in.
> >
> > It's done in the DSP processors that handle all other receiver tasks.
Not
> > sure who might have led you to believe that there were dedicated or
> > specialized NR processors. As far as I know, NR is implemented as some
> form
> > of LMS alogrithm, as it is in most other radios in the ham market.
> >
> > Grant/NQ5T
> >
> > _______________________________________________
> > TenTec mailing list
> > TenTec@contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
> >
> >
>
>
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