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Sci.Electronics.Basics -> Questions about equivalents of audio/video and digital/analog.
There are 304 messages in this thread.
You are currently looking at messages 100 to 120.
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Author: Scott SeidmanDate: 17:43 20-08-07
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floyd@apaflo.com (Floyd L. Davidson) wrote in
news:87mywlki1d.fld@apaflo.com:
> Sheesh! That *is*, by definition a digital signal.
>
Funny, that's just what my D/A converters put out, and the spec sheets
claim they're putting out analog signals. Perhaps I should return them.
--
Scott
Reverse name to reply
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Author: Don PearceDate: 17:57 20-08-07
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On Mon, 20 Aug 2007 13:33:34 -0800, floyd@apaflo.com (Floyd L.
Davidson) wrote:
>nospam@nospam.com (Don Pearce) wrote:
>>On Mon, 20 Aug 2007 05:46:19 -0800, floyd@apaflo.com (Floyd L.
>>Davidson) wrote:
>>
>>>nospam@nospam.com (Don Pearce) wrote:
>>>>On Mon, 20 Aug 2007 04:57:03 -0800, floyd@apaflo.com (Floyd L.
>>>>Davidson) wrote:
>>>>
>>>>>Jerry Avins <jya@ieee.org> wrote:
>>>>>>I like your categories. It is possible in concept to
>>>>>>have a signal that is quantized in magnitude and
>>>>>>continuous in time, but (unless we resort to counting
>>>>>>electrons) I don't think it's possible in practice.
>>>>>
>>>>>If you quantize the magnitude, it is digital. That is
>>>>>by definition.
>>>>
>>>>No it isn't. It isn't digital until you assign numerical values to
>>>>those quantized levels. Until then it is simply a quantized analogue
>>>>signal.
>>>
>>>If you quantize it, you *have* assigned a value to it,
>>>and that value is not from a continuous set, but from a
>>>discrete finite set, and therefore it is digital.
>>>
>>>A "quantized analogue signal" is digital by definition.
>>>
>>
>>No, you haven't. You merely have a signal at a set of discrete levels.
>
>Sheesh! That *is*, by definition a digital signal.
>
If you put that signal through an analogue amplifier, it will be
amplified. That makes it an analogue signal. If you want to amplify a
signal in the digital domain, you must perform maths on the numbers.
Can you really not see the difference?
>>You need an analogue to digital converter to take each of those
>>quantized levels and convert it into a digital word (of 1s and 0s).
>>
>>Digital means "represented by digits", not "in discrete voltage
>>steps".
>
>Bullshit son. Look it up. I've provided you with
>quotes from an authoritative reference, twice now. You
>don't have to take my word for it, that *is* the agreed
>technical definition of the term.
Sorry, but you are wrong. And any reference you have found that makes
such a claim is not authoritative; it is also wrong.
d
--
Pearce Consulting
http://www.pearce.uk.com
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Author: Floyd L. DavidsonDate: 17:57 20-08-07
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nospam@nospam.com (Don Pearce) wrote:
>On Mon, 20 Aug 2007 11:31:16 -0400, Randy Yates <yates@ieee.org>
>wrote:
>
>>nospam@nospam.com (Don Pearce) writes:
>>> [...]
>>> On Mon, 20 Aug 2007 05:46:19 -0800, floyd@apaflo.com (Floyd L.
>>> Davidson) wrote:
>>>
>>>>A "quantized analogue signal" is digital by definition.
>>>>
>>>
>>> No, you haven't. You merely have a signal at a set of discrete levels.
>>> You need an analogue to digital converter to take each of those
>>> quantized levels and convert it into a digital word (of 1s and 0s).
>>>
>>> Digital means "represented by digits", not "in discrete
voltage
>>> steps".
>>
>>I've never seen that definition, while I have seen the definition
>>Floyd is proposing, and I think it is a reasonable one.
>>
>No, it isn't. It misses the fact that sampled and digital are
>different things. Digits are numbers.
Are you kidding? It is *the* industry standard
definition. It is not something that I made up, I
merely looked it up.
http://ntia.its.bldrdoc.gov/fs-1037/
That is, since you seem unable to grasp or investigate
it, the web site of the National Telecommunications and
Information Administration, a part of the US Federal
Department of Commerce, in Boulder Colorado. Which is
to say they are next door to and under that same
management as the NIST (the National Institute of
Standards and Technology), and NOAA (National Oceanic
and Atmospheric Administration) which you may also have
heard of...
Or, to put it another way, you will not find anywhere in
the world a valid definition that disagrees with that
one. If yours is not in agreement, you are *wrong*.
>>I've also seen many contexts in which "digital" means
"discrete-time,"
>>i.e., there is no amplitude quantization at all. Take for example any
>>of a number of books on the subject which have "digital signal
>>processing" in the title - they are referring to signals that have
>>been sampled in time, but not quantized (generally, although
>>quantization effects are also analyzed in several such texts).
>>
>
>Really? Can you point me at something that does DSP on signals that
>have been merely sampled in time? I've never come across any such
>thing.
>
>>Do you have a reference for your definition?
>
>Logic will do.
Logically you are walking the plank. Such technical
definitions have nothing to do with logic. It is an
arbitrary decision that it means this or it means that.
If we all agree on the arbitrary decision then we have a
standard, and we can use it knowing that others will
understand what it means.
Until someone like you walk in and says they have their
own definition...
>If you are doing digital signal processing, you are
>doing arithmetic on the numbers that come out of an AtoD converter.
That is not necessarily true. Not all digital signals
originate as analog signals that require A->D
conversion.
>You can't do that with some voltage levels out of a quantizer.
Out of a quantizer? You certainly can.
>As for discrete time, that is simply sampled, like a class D
>amplifier, and nothing to do with digits. There is plenty of laziness
>in the use of nomenclature (as well as misuse by people who simply
>have no idea what they are talking about).
I totally agree with that statement. ;-)
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>;
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
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Author: Don PearceDate: 18:00 20-08-07
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On 20 Aug 2007 21:42:18 GMT, Scott Seidman
<namdiesttocs@mindspring.com> wrote:
>floyd@apaflo.com (Floyd L. Davidson) wrote in
>news:87zm0mjrfy.fld@apaflo.com:
>
>>>quantized - a sampled signal, but with the possible levels constrained
>>>to a limited set of values
>>
>> That is by definition a digital siganl. As soon as the possible values
>> are "constrained to a limited set", it is by definition digital data.
>>
>>
>
>Wouldn't this make the output of a D/A converter digital by definition?
It certainly would. But apparently there are those that can't see the
difference between a limited set of values, and a set of numbers
describing those values.
d
--
Pearce Consulting
http://www.pearce.uk.com
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Author: Jerry AvinsDate: 18:22 20-08-07
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Scott Seidman wrote:
> floyd@apaflo.com (Floyd L. Davidson) wrote in
> news:87zm0mjrfy.fld@apaflo.com:
>
>>> quantized - a sampled signal, but with the possible levels constrained
>>> to a limited set of values
>> That is by definition a digital siganl. As soon as the possible values
>> are "constrained to a limited set", it is by definition digital data.
>>
>>
>
> Wouldn't this make the output of a D/A converter digital by definition?
Of course it would. I think it's a bit silly (pretty stupid, actually)
to argue about what to call something and believe that's the same as
arguing about what it is. One could say that a continuous signal
measured with a 3.5-digit meter is quantized by the measurement even if
it's unchanged thereby. And if the signal is recorded hourly in a log
book, I suppose it becomes sampled. Is it worth trying to make a
definition that withstands all possible logical contortions? Probably
sometimes, but not here; not now.
Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
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Author: Floyd L. DavidsonDate: 18:22 20-08-07
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"Bob Myers" <nospamplease@address.invalid> wrote:
>"Randy Yates" <yates@ieee.org> wrote in message
>news:m31wdytcq2.fsf@ieee.org...
>>>>I've never seen that definition, while I have seen the definition
>>>>Floyd is proposing, and I think it is a reasonable one.
>>>>
>>> No, it isn't. It misses the fact that sampled and digital are
>>> different things. Digits are numbers.
>>
>> It isn't reaonable to you. Don't publish opinion as fact.
>
>OK, it's not reasonable to ME, either, if you're impressed
>by taking a vote on this sort of thing.
>
>The problem with the definition that you and Floyd seem to
>want to use is that it leads to several problems in both
>theory and practice, in addition to the fact that there are
>numerous counter-examples one can point to.
It doesn't lead to any such problems.
What you need to get straight is that it is not *my*
definition. It is the *standard* technical definition
recognized by virtually *every* standards organization.
I quoted the NTIA's Federal Standard 1037C.
>"Reasonable" would seem (at least to me) to mean that you
It makes no difference what you think is or is not
reasonable, unless we want to discuss *you*. If you
disagree with the standard definition then you don't
understand the term, and we can determine how far off
you are by how much your definition differs from that
one! ;-)
>can justify your definition *through reason*, which Don has
>done.
Which proves that he doesn't understand it. It says
nothing about whether the National Telecommunications
and Information Administration, knows or what the MilStd
specification knows.
>Simply pointing to a published work, including a
>standard, as a reference to support your definition is what's
>called an "argument from authority," and it has exactly zero
That is a logical fallacy on your part. An "argument
from authority" has great weight if it is valid. To
be valid it must pass three tests:
1) The authority cited must actually be an authority.
2) All authorities must agree on the topic.
3) The authority cannot be misquoted, taken out of
context, or be joking.
Clearly citing the NTIA and MilStd definition is indeed
a *very* strong appeal to authority, and no mere opinion
can even come close to invalidating it.
>weight in light of an opposing argument based on evidence
>and logic.
What evidence? And the logic is clearly invalid and
based on false assumptions.
You know one way to be absolutely positive that your
logic is not good is to do a reality check and find that
the answer you have is wrong. It this case that is very
easy to do, which is why *standard* definitions are
quoted from authoritative sources. If you disagree,
then clearly you *don't* have the logic right!
>However, if you like, I can also point to several
>references which support the definition that Don and I (and
So cite even one such valid reference! (You *cannot*,
because there are none.)
(And recognize that if you think you have one, then
there is one of two things clearly true: Either 1) you
do not understand that the other definition is not
actually different, or 2) your reference is not a valid
one.)
>I believe others) are proposing. You might claim the list to
>be invalid, however, since it would contain works that I
>myself wrote for publication. Which is, of course, the whole
You are not a valid reference. You don't even come
close to being equal to the NTIA.
And it is *hilarious* that you would (again, because
this isn't the first time) try to convince anyone that
you are.
>point - simply having your statements published does NOT
>make them any more or less correct; the deciding factor is
>whether or not they can be shown to be true through evidence
>and logic.
Except technical definitions are sometimes merely
arbitrary agreements on one of many possible logical
ways to define a term. We could have decided that
"digital" means binary, or a decimal system. We didn't,
but both would be logical.
>A common misuse or misunderstanding does not become
>less so merely because it IS common.
Hmmm...
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>;
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
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Author: Floyd L. DavidsonDate: 18:42 20-08-07
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"Bob Myers" <nospamplease@address.invalid> wrote:
>"Floyd L. Davidson" <floyd@apaflo.com> wrote in message
>news:87r6lyjp3o.fld@apaflo.com...
>
>> A "quantized analogue signal" is digital by definition.
>
>No, Don had it right. A quantized analog signal
You can repeat that all you like, but you are wrong
every time you do.
By *definition* it is a digital signal.
quantization:
A process in which the continuous range of values
of an analog signal is sampled and divided into
nonoverlapping (but not necessarily equal)
subranges, and a discrete, unique value is assigned
to each subrange.
A _sampled_ signal is still analog. A _quantized_ signal is
digital by definition.
If you do not stay with standard definitions it is
impossible to discuss anything rationally.
>remains analog as long as the relative values of the
>quantization levels, one to the other have significance;
>they thus can carry information, which is the fundamental
>goal of any such system.
The quantization levels are digital. By definition.
If that isn't what you mean, then you need to use other
words because you are confusing the issue by misuse of
standard terms.
>Now, we could certainly assign values to those levels
>which (for instance) are NOT in order from "top to
>bottom" (or whichever direction you choose to use),
>which might be done to distribute the susceptibility of
>any given "bit" in said value to noise evenly. In this
>case, the levels MUST be interpreted as the intended
>numeric values in order to recover the original
>information, and hence this would be a "digital"
>encoding system.
>
>> QUANTIZATION:
>> A process in which the continuous range of values
>> of an analog signal is sampled and divided into
>> nonoverlapping (but not necessarily equal)
>> subranges, and *a* *discrete*, *unique* *value* *is*
>> *assigned* to each subrange.
>>
>> http://ntia.its.bldrdoc.gov/fs-1037/
>
>Exactly. But mere quantization by itself does not
>suffice to render a signal "digitally encoded," no
>matter what a given government "expert" may claim.
The quantization of a signal makes it digital.
(It *is* encoded, too, BTW. But until you understand
what makes it digital, there is little point in trying
to define what "encoded" means.)
No matter how dense you want to be about it, that
government "expert" happens to be right. And you cannot
find *any* expert that will disagree. That is the
*standard* definition, and virtually *everyone* agrees
that it is correct.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>;
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
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Author: Floyd L. DavidsonDate: 18:56 20-08-07
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Don Bowey <dbowey@comcast.net> wrote:
>On 8/20/07 8:41 AM, in article faccmf$sfh$1@usenet01.boi.hp.com, "Bob
Myers"
><nospamplease@address.invalid> wrote:
>
>>
>> "Floyd L. Davidson" <floyd@apaflo.com> wrote in message
>> news:87r6lyjp3o.fld@apaflo.com...
>>
>>> A "quantized analogue signal" is digital by definition.
>>
>> No, Don had it right. A quantized analog signal
>> remains analog as long as the relative values of the
>> quantization levels, one to the other have significance;
>> they thus can carry information, which is the fundamental
>> goal of any such system.
>
>No, it becomes a digitally encoded representative of a sample of an analog
>voltage. First the continuously variable analog signal is sampled,
>becoming, for example PAM, which is still analog, which is then quantized
>and may be fit to whatever digital or analog coding that is desired. If
Once it is quantized, it is digital.
Actually I suspect it is open to debate as to whether a
sample is actually PAM until it is quantized. (Until it
is, it's just a sample of an analog signal.) But
whatever, if the sample itself actually is PAM, then yes
that is an analog signal.
However, after it is is quantized is then a digital (PAM)
signal. (And example is the high speed link of a v.90
modem, which uses PAM.)
>it's to a digital code, the signal is digital. If to an analog code, the
>signal is analog.
For analog it necessarily has to be _modulated_, not
encoded. If must be modulated for the resulting signal
to be applied to the input of an analog channel. If it
is encoded it must a digital channel. (Again, that is
the nature of arbitrary definitions, this time of what
"encode" and "modulate" mean.)
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>;
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
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Author: Floyd L. DavidsonDate: 19:01 20-08-07
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Jerry Avins <jya@ieee.org> wrote:
>Floyd L. Davidson wrote:
>> nospam@nospam.com (Don Pearce) wrote:
>>> On Mon, 20 Aug 2007 04:57:03 -0800, floyd@apaflo.com (Floyd L.
>>> Davidson) wrote:
>>>
>>>> Jerry Avins <jya@ieee.org> wrote:
>>>>> I like your categories. It is possible in concept to
>>>>> have a signal that is quantized in magnitude and
>>>>> continuous in time, but (unless we resort to counting
>>>>> electrons) I don't think it's possible in practice.
>>>> If you quantize the magnitude, it is digital. That is
>>>> by definition.
>>> No it isn't. It isn't digital until you assign numerical values to
>>> those quantized levels. Until then it is simply a quantized analogue
>>> signal.
>> If you quantize it, you *have* assigned a value to it,
>> and that value is not from a continuous set, but from a
>> discrete finite set, and therefore it is digital.
>> A "quantized analogue signal" is digital by definition.
>> (Emphasis added)
>> QUANTIZATION:
>> A process in which the continuous range of values
>> of an analog signal is sampled and divided into
>> nonoverlapping (but not necessarily equal)
>> subranges, and *a* *discrete*, *unique* *value* *is*
>> *assigned* to each subrange.
>> http://ntia.its.bldrdoc.gov/fs-1037/
>
>The government declares it so it must be true?
No, virtually *every* standards organization recognizes
that definition.
You cannot find *any* reputable disagreement.
(For one thing, because anyone who disagrees is *clearly*
not credible... ;-)
>I can
>demonstrate a circuit using analog components that
>transforms a continuous ramp input into a staircase
>output. Moreover, the output levels can be individually
>adjusted. Is the output digital? (We're discussing an
>arbitrary definition here. There is no wrong answer.)
The output is apparenlty analog. At least you have said
*nothing* that indicates otherwise.
Do you think all digital signals are square waves and
anything that has square waves is digital? Your example
above suggests that you might, but it simply isn't true.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>;
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
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Author: Floyd L. DavidsonDate: 19:10 20-08-07
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Jerry Avins <jya@ieee.org> wrote:
>Floyd L. Davidson wrote:
>> Jerry Avins <jya@ieee.org> wrote:
>>> I like your categories. It is possible in concept to
>>> have a signal that is quantized in magnitude and
>>> continuous in time, but (unless we resort to counting
>>> electrons) I don't think it's possible in practice.
>> If you quantize the magnitude, it is digital. That is
>> by definition.
>
>I believe that the definition is flawed. Not that it
Your opinion of standard definitions is worthless.
If you want to communicate with the rest of the technical
world, use standard definitions and cease claiming they
are flawed.
Your opinion is where the flaw exists.
>matters; it's good enough in context. A signal can be
>quantized without any need to measure it or describe it
>with a number.
That isn't true. In order to quantize it you *must*
decide on non-overlapping ranges of *values*, and a
specific quantity value that equates to those values.
>An example is the signal being measured
>in a quantum Hall-effect experiment.
Explain.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>;
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
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Author: Floyd L. DavidsonDate: 19:14 20-08-07
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"Bob Myers" <nospamplease@address.invalid> wrote:
>"Dave Platt" <dplatt@radagast.org> wrote in message
>news:8ponp4-gfd.ln1@radagast.org...
>> >Come on, Dave, a CCD is a digital device, subject to aliasing. The
>>>charges represent the signal at a particular instant of its average over
>>>a particular interval. (My CCD digital camera can take time exposures.)
>>>A CCD's content may not be quantized in amount, but it is quantized in
>>>time. In a camera, where the charges pertain to individual pixels, the
>>>result is also quantized in space.
>>
>> "Digital" and "subject to aliasing" are two different
things.
>>
>> As I believe the term "digital" is usually meant, it implies a
>> two-state (on/off) storage representation.
>
>Not necessarily; a two-state representation is most properly
>referred to as "binary." The best definition of "digital" I've
>managed to come up with comes in the word itself - it
>is the encoding system whereby information is stored as
>"digits," i.e., numeric values, as opposed to a system in which
>the information is stored "analogously" in the form of one
>parameter (voltage, say) which varies in a like manner as the
>original.
Your definition is flawed. Digital implies a finite set
of values, which might well be a voltage that varies in
a like manner (granted not continuously) as the
original.
Analog inplies the variation is continuous.
>"Quantized" and "sampled" are terms which are really not all
>that closely associated (at least in theory) with either of the
>above,
Again, not really true. Quantized is necessarily
digitized.
But sampled can be either.
>although admittedly most systems seen today which
>employ sampling and/or quantization are also "digital" in the
>nature of the encoding of the information carried.
Anything that is quantized is digitized.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>;
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
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Author: Floyd L. DavidsonDate: 19:22 20-08-07
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Author: Floyd L. DavidsonDate: 19:28 20-08-07
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"Bob Myers" <nospamplease@address.invalid> wrote:
>"Floyd L. Davidson" <floyd@apaflo.com> wrote in message
>news:87zm0mjrfy.fld@apaflo.com...
>>>digital - a quantized signal, with the individual levels represented
>>>by numbers
>>
>> It makes no difference how the levels are represented.
>
>Sure it does.
Look up the definition of "quantization" again. It simply
makes no difference. If an analog signal is quantized, the
result is a digital signal. That is by definition, and you
cannot escape that with mumbo-jumbo and faulty logic.
>If the levels of the original signal (or rather,
>whatever parameter of the original information is being
>recorded/stored/process are represented by analogous
>levels of some other parameter (e.g., sound represented
>by voltage), then the system is "analog."
And that necessarily means that the "analogous levels"
can vary continuously.
(Your example is poor, becuase sound can be represented
by a voltage that has been digitally encoded.)
>It is certainly
>possible to conceive of a quantized analog system, although
It is not possible by definition. If you quantize something,
you have a finite set of discrete values, and it *is* digital.
>such things are rarely if ever seen in practice.
Understatement of the day.
>"Analog" also does not imply "infinite" precision or
>adjustability, since, as is the case in ALL systems, the achievable
>precision (and thus the information capacity) is ultimately limited
>by noise. See the Gospel According to St. Shannon for
>further details...;-)
True. It means only continuously variable over an
infinite set of values. Your ability to determine
exactly which value (accuracy) is not guaranteed, nor is
your ability to reset to any specific value (precision)
guaranteed.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>;
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
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Author: Floyd L. DavidsonDate: 19:29 20-08-07
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glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote:
>Bob Myers wrote:
>
>(snip)
>
>> "Analog" also does not imply "infinite" precision or
>> adjustability, since, as is the case in ALL systems, the achievable
>> precision (and thus the information capacity) is ultimately limited
>> by noise. See the Gospel According to St. Shannon for
>> further details...;-)
>
>How about, Analog implies "infinite" precision in the absence of
>noise, including fundamental quantum noise.
>
>Note, for example, that an analog current is quantized in units
>of the charge on the electron.
No, in fact it is not. Electrons do not necessarily all move
at the same speed...
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>;
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
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Author: Floyd L. DavidsonDate: 19:32 20-08-07
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Author: Floyd L. DavidsonDate: 19:49 20-08-07
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"Bob Myers" <nospamplease@address.invalid> wrote:
>"glen herrmannsfeldt" <gah@ugcs.caltech.edu> wrote in message
>news:E6ednXh1JIkcRlTbnZ2dnUVZ_hynnZ2d@comcast.com...
>
>> How about, Analog implies "infinite" precision in the absence of
>> noise, including fundamental quantum noise.
>
>Except that "absence of noise" is a condition which
>doesn't exist, even in theory.
Apparenlty Claude Shannon didn't agree with you on that.
Part I of "A Mathematical Theory of Communications" carries
the title "Discrete Noiseless Systems". Section 1 of that
part is titled "The Discrete Noiseless Channel". It turns
out that is a very important theoretical model.
>ALL systems, digital, analog, or whatever, are limited in
>information capacity by (a) the bandwidth of the channel
>in question and (b) the level of noise within that channel,
>per the aforementioned Gospel According to Shannon.
>This is exactly the same thing as saying that there is a limit
>to "precision" or "accuracy," as infinite precision implies
>an infinite information capacity (i.e., given infinite precision,
>I could encode the entire Library of Congress as a single
>value, since I have as many effective "bits of resolution"
>as I would ever need).
>
>> Note, for example, that an analog current is quantized in units
>> of the charge on the electron.
>
>Sure is. So isn't it a good thing that we don't confuse either
>"analog" or "digital" with either "quantized" or
"continuous"?
Backwards.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>;
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
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Author: Don BoweyDate: 19:52 20-08-07
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On 8/20/07 11:58 AM, in article 5iu6iuF3qsf7aU1@mid.individual.net, "Richard
Crowley" <rcrowley@xp7rt.net> wrote:
> Radium's ability to suck so many people into attempting to
> answer insane questions is reaching legendary heights.
> I hereby nominate him for the Troll Hall of Fame with special
> endorsement for use of technical gobeldygook.
>
>
He does have a knack for getting into esoteric points before having an
understanding foundation. Not insane, but all over the map.
I'll vote for your candidate, in any case.
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Author: RadiumDate: 20:17 20-08-07
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On Aug 20, 12:11 am, nos...@nospam.com (Don Pearce) wrote:
> analogue - a continuous representation of the original signal
> sampled - a representation of the signal at discrete time points
> quantized - a sampled signal, but with the possible levels constrained
> to a limited set of values
> digital - a quantized signal, with the individual levels represented
> by numbers
I agree with your list.
That means the device in the link below is neither analog nor
digital.
http://www.winbond-usa.com/mambo/content/view/36/140/
I'd like to see a purely-analog device which can record, store, and
playback electric audio signals [AC currents at least 20 Hz but no
more than 20,000 Hz] without having any moving parts [except of course
for the diaphragms present in the microphone and speaker and the
electrons that make up the electric signal] and without any amount of
sampling.
The CCD is out of the question as it uses sampling.
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Author: Scott SeidmanDate: 20:25 20-08-07
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Radium <glucegen1@gmail.com> wrote in news:1187655470.606369.55890
@j4g2000prf.googlegroups.com:
> That means the device in the link below is neither analog nor
> digital.
Or more accurately, both analog and digital.
--
Scott
Reverse name to reply
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Author: Floyd L. DavidsonDate: 20:29 20-08-07
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Scott Seidman <namdiesttocs@mindspring.com> wrote:
>floyd@apaflo.com (Floyd L. Davidson) wrote in
>news:87mywlki1d.fld@apaflo.com:
>
>> Sheesh! That *is*, by definition a digital signal.
>>
>
>Funny, that's just what my D/A converters put out, and the spec sheets
>claim they're putting out analog signals. Perhaps I should return them.
Your D/A converter puts out what is called
"quasi-analog". It's actually a digital PAM signal, not
an analog signal.
You can easily make it is a close approximation of the
original (with quantization distortion added), however,
But once you do that (by sending it through almost any
kind of an analog channel) it truly becomes "analog", in
the sense that you can no longer recover information or
use it as a digital signal.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>;
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com
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