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Sci.Electronics.Basics -> AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency

There are 269 messages in this thread.
You are currently looking at messages 240 to 260.






Author: Ron Baker, Pluralitas!
Date: 12:26 08-07-07



"isw" <isw@witzend.com> wrote in message
news:isw-664E24.21491207072007@newsgroups.comcast.net...
> In article <468fe7df$0$16560$4c368faf@roadrunner.com>,
> "Ron Baker, Pluralitas!" <this@aint.me> wrote:
>
>
> --snippety-snip--
>
>> >> You said you are a physicist/engineer.
>> >> What does "linear" mean?
>> >
>> > Let's not get too far off the subject here. We were discussing whether
>> > the "tuning beat" that you use to tune a musical instrument
involved a
>> > nonlinear process (ie. "modulation").
>>
>> Then linearity is at the core of the matter.
>> What does "linear" (or "nonlinear") mean to you?
>
> OK, if you insist -- *in this case* it means "linear enough to not
> produce IM products of significant amplitude".

Good enough.
Then spectrum analyzers and the human auditory
system are not linear.
Stay with me here.

>
>> > I said that it does not, and that
>> > it could be detected by instrumentation which was proveably linear
>> > (i.e.
>> > not "perfectly" linear, because that's not required, but
certainly
>> > linear enough to discount the requirement for "modulation").
>>
>> No nonlinearity is necessary in order to hear
>> a beat?
>> Where does the beat come from?
>
> As the phase of the two nearly equal waves move past each other, there
> is simple vector summation which varies the amplitude.
>
> Consider two sine waves of precisely the same frequency, where one of
> them is adjustable in phase -- use a goniometer, for instance. Use a set
> of resistors to sum the two signals, and observe the summing point with
> a 'scope or a loudspeaker. By altering the phase of one source, you can
> get any amplitude you want from zero up to twice the amplitude of either
> one.
>
> Now just twiddle that phase knob around and around as fast as you can.
>
> You've just slightly altered the instantaneous frequency of one of the
> generators (but only while you twiddle), and accomplished pretty much
> the same effect as listening to the beat between two guitar strings at
> nearly zero frequency offset. With no nonlinear processes in sight.
>
> Isaac

You put some effort into that. I give you
credit for that.

The socratic thing isn't working, so here
you go.

Is an envelope detector linear? The answer is no.
But how can that be? If you put in a sine wave of
amplitude A you get A volts out (assuming its gain is 1).
If you put in a sine wave of amplitude 2A and you
get 2A volts out. Linear, right?
Now you put in a sine wave of amplitude A at
455 kHz plus a sine wave of amplitude A at
456 kHz. (Consider the envelope detector
of a typical AM radio here.) What do you get out? A
sine wave of amplitude A/2 at 1 kHz. Intermodulation.
An envelope detector is not linear. No envelope/
amplitude detector is linear.

The typical envelope detector is a diode rectifier
followed by a lowpass filter.
The diode rectifier is obviously nonlinear and
gives you all sorts of intermoduation. With a
single sine wave input you get a DC term and
various harmonics of the sine wave. The lowpass
filter filters out all the harmonics and leaves
the DC.
If you put in two sine waves (assuming their
frequencies are above the cutoff of the subsequent
lowpass and their difference is within the
lowpass) again the diode nonlinearity results
in intermodulation. You get a DC component,
the difference frequency, the sum, and various
higher frequencies. The filter leaves only the
difference frequency and the DC. In an AM
receiver the DC is subsequently blocked too.

Do you see how this applies to spectrum analyzers
and the human auditory system?



Author: isw
Date: 13:58 08-07-07

In article <46910fe5$0$8925$4c368faf@roadrunner.com>,
"Ron Baker, Pluralitas!" <this@aint.me> wrote:

> "isw" <isw@witzend.com> wrote in message
> news:isw-664E24.21491207072007@newsgroups.comcast.net...
> > In article <468fe7df$0$16560$4c368faf@roadrunner.com>,
> > "Ron Baker, Pluralitas!" <this@aint.me> wrote:
> >
> >
> > --snippety-snip--
> >
> >> >> You said you are a physicist/engineer.
> >> >> What does "linear" mean?
> >> >
> >> > Let's not get too far off the subject here. We were discussing
whether
> >> > the "tuning beat" that you use to tune a musical instrument
involved a
> >> > nonlinear process (ie. "modulation").
> >>
> >> Then linearity is at the core of the matter.
> >> What does "linear" (or "nonlinear") mean to you?
> >
> > OK, if you insist -- *in this case* it means "linear enough to not
> > produce IM products of significant amplitude".
>
> Good enough.
> Then spectrum analyzers and the human auditory
> system are not linear.
> Stay with me here.
>
> >
> >> > I said that it does not, and that
> >> > it could be detected by instrumentation which was proveably linear
> >> > (i.e.
> >> > not "perfectly" linear, because that's not required, but
certainly
> >> > linear enough to discount the requirement for
"modulation").
> >>
> >> No nonlinearity is necessary in order to hear
> >> a beat?
> >> Where does the beat come from?
> >
> > As the phase of the two nearly equal waves move past each other, there
> > is simple vector summation which varies the amplitude.
> >
> > Consider two sine waves of precisely the same frequency, where one of
> > them is adjustable in phase -- use a goniometer, for instance. Use a set
> > of resistors to sum the two signals, and observe the summing point with
> > a 'scope or a loudspeaker. By altering the phase of one source, you can
> > get any amplitude you want from zero up to twice the amplitude of either
> > one.
> >
> > Now just twiddle that phase knob around and around as fast as you can.
> >
> > You've just slightly altered the instantaneous frequency of one of the
> > generators (but only while you twiddle), and accomplished pretty much
> > the same effect as listening to the beat between two guitar strings at
> > nearly zero frequency offset. With no nonlinear processes in sight.
> >
> > Isaac
>
> You put some effort into that. I give you
> credit for that.
>
> The socratic thing isn't working, so here
> you go.

I would appreciate it if you would take the time to list *in detail* any
errors in what I wrote. If it "isn't working", I need to know why,
because I don't like to be confused about things.

> Is an envelope detector linear? The answer is no.

That's correct, and I'm well aware of it, but so what?

--dissertation on how an envelope detector works snipped--

> Do you see how this applies to spectrum analyzers
> and the human auditory system?

Sure. But

1) It is possible -- if not practical -- to build a "detectorless" (in
the nonlinear process sense) spectrum analyzer, and

2) None of it is even remotely significant to the subject at hand.

Here it is again: the "beat" one hears when tuning a guitar or other
instrument does *not* require any nonlinear process for its production.
Period.

Isaac

Author: isw
Date: 14:03 08-07-07

In article <469064fd$0$16540$4c368faf@roadrunner.com>,
"Ron Baker, Pluralitas!" <this@aint.me> wrote:

--big ol' snip--

> >>> When AM is correctly accomplished (a single voiceband signal is
> >>> modulated
> >>
> >> The questions I posed were not about AM. The
> >> subject could have been viewed as DSB but that
> >> wasn't the specific intent either.
> >
> > You should take some time to more carefully frame your questions.
> >
> > Do you understand that a DSB signal *is* AM?
>
> So all the AM broadcasters are wasting money by
> generating a carrier?

Of course not. They're saving you (and everybody else) money by allowing
simple receiver designs -- and that was very important in the 1920's.

Isaac

Author: Bob Myers
Date: 14:11 08-07-07


"Ron Baker, Pluralitas!" <this@aint.me> wrote in message
news:4690647b$0$24729$4c368faf@roadrunner.com...
>> For the simple reason that there isn't actually a "tone" involved -
>> in other words, there is no actual signal at the difference frequency.
>> There can't be, since there is no "mixing" (multiplication) of the
>> two original tones.
>
> There is no multiplication of 1000 Hz and 1005 Hz
> either, is there? Why don't you hear 1000 Hz and
> 1005 Hz rather than a single tone varying in amplitude?

Because you can't distinguish two tones as separate tones
if they are close enough together in frequency, due to the
way in which the frequency-discrimination process in human
hearing operates.


> Could it be that the human auditory system is not
> linear?

There are a number of ways in which the human auditory
system is not linear; it's simply that these are not the dominant
cause of the perception of audible "beats."

Bob M.



Author: Ron Baker, Pluralitas!
Date: 23:50 09-07-07


"craigm" <none@domain.invalid> wrote in message
news:nDuji.3$ff6.170151@news.sisna.com...
> isw wrote:
>
>>> > What is the difference between AM and DSB?
>>> >
>>> >
>>> >
>>>
>>> AM is a process. DSB (double sideband), with carrier, is it's most
>>> simple
>>> result. DSB without carrier (suppressed carrier dsb) requires using, at
>>> least, a balanced mixer as the AM multiplier.
>>
>> And requires, for proper reception, that a carrier be recreated at the
>> receiver which has not only the amplitude of the original, but also its
>> exact phase. Absent some sort of "pilot" to get things synchronized,
>> this makes reception very difficult.
>>
>> Isaac
>
>
> Try a Costas loop.
>

Interesting. I had heard of that in reference to
BPSK but hadn't considered it for DSB. Yes,
that would work.



Author: Ron Baker, Pluralitas!
Date: 23:58 09-07-07


"Dana" <raff242@yahoo.com> wrote in message
news:80b7c$46906e83$944e306e$20475@STARBAND.NET... /> >
> "Ron Baker, Pluralitas!" <
this@aint.me> wrote in message
> news:469064fd$0$16540$4c368faf@roadrunner.com...
>>> Do you understand that a DSB signal *is* AM?
>>
>> So all the AM broadcasters are wasting money by
>> generating a carrier?
>
> How did you jump to that conclusion.

Is "DSBSC" DSB?



Author: Dana
Date: 00:05 10-07-07


"Ron Baker, Pluralitas!" <this@aint.me> wrote in message
news:4693037c$0$31221$4c368faf@roadrunner.com...
>
> "Dana" <raff242@yahoo.com> wrote in message
> news:80b7c$46906e83$944e306e$20475@STARBAND.NET... /> >>
>> "Ron Baker, Pluralitas!" <
this@aint.me> wrote in message
>> news:469064fd$0$16540$4c368faf@roadrunner.com...
>>>> Do you understand that a DSB signal *is* AM?
>>>
>>> So all the AM broadcasters are wasting money by
>>> generating a carrier?
>>
>> How did you jump to that conclusion.
>
> Is "DSBSC" DSB?

Why can't you answer the question?
How or why do you think AM broadcasters are wasting money by generating a
carrier??

>
>



Author: Ron Baker, Pluralitas!
Date: 01:54 10-07-07


"isw" <isw@witzend.com> wrote in message
news:isw-97799B.10580608072007@newsgroups.comcast.net...
> In article <46910fe5$0$8925$4c368faf@roadrunner.com>,
> "Ron Baker, Pluralitas!" <this@aint.me> wrote:
>
>> "isw" <isw@witzend.com> wrote in message
>> news:isw-664E24.21491207072007@newsgroups.comcast.net...
>> > In article <468fe7df$0$16560$4c368faf@roadrunner.com>,
>> > "Ron Baker, Pluralitas!" <this@aint.me> wrote:
>> >
>> >
>> > --snippety-snip--
>> >
>> >> >> You said you are a physicist/engineer.
>> >> >> What does "linear" mean?
>> >> >
>> >> > Let's not get too far off the subject here. We were discussing
>> >> > whether
>> >> > the "tuning beat" that you use to tune a musical
instrument involved
>> >> > a
>> >> > nonlinear process (ie. "modulation").
>> >>
>> >> Then linearity is at the core of the matter.
>> >> What does "linear" (or "nonlinear") mean to you?
>> >
>> > OK, if you insist -- *in this case* it means "linear enough to not
>> > produce IM products of significant amplitude".
>>
>> Good enough.
>> Then spectrum analyzers and the human auditory
>> system are not linear.
>> Stay with me here.
>>
>> >
>> >> > I said that it does not, and that
>> >> > it could be detected by instrumentation which was proveably
linear
>> >> > (i.e.
>> >> > not "perfectly" linear, because that's not required,
but certainly
>> >> > linear enough to discount the requirement for
"modulation").
>> >>
>> >> No nonlinearity is necessary in order to hear
>> >> a beat?
>> >> Where does the beat come from?
>> >
>> > As the phase of the two nearly equal waves move past each other, there
>> > is simple vector summation which varies the amplitude.
>> >
>> > Consider two sine waves of precisely the same frequency, where one of
>> > them is adjustable in phase -- use a goniometer, for instance. Use a
>> > set
>> > of resistors to sum the two signals, and observe the summing point with
>> > a 'scope or a loudspeaker. By altering the phase of one source, you can
>> > get any amplitude you want from zero up to twice the amplitude of
>> > either
>> > one.
>> >
>> > Now just twiddle that phase knob around and around as fast as you can.
>> >
>> > You've just slightly altered the instantaneous frequency of one of the
>> > generators (but only while you twiddle), and accomplished pretty much
>> > the same effect as listening to the beat between two guitar strings at
>> > nearly zero frequency offset. With no nonlinear processes in sight.
>> >
>> > Isaac
>>
>> You put some effort into that. I give you
>> credit for that.
>>
>> The socratic thing isn't working, so here
>> you go.
>
> I would appreciate it if you would take the time to list *in detail* any
> errors in what I wrote. If it "isn't working", I need to know why,
> because I don't like to be confused about things.
>
>> Is an envelope detector linear? The answer is no.
>
> That's correct, and I'm well aware of it, but so what?

No you're not.

"Yup. And the spectrum analyzer is (hopefully) a very linear system,
producing no intermodulation of its own."

Hopefully?

Is a spectrum analyzer linear?
"I'm sure there's more than one way to do it, but I feel certain..."
Dodging the question.

Which of them is linear?

"a bolometer just turns the signal power into heat; nothing
nonlinear there..."

(Bolometers are no more linear than envelope detectors.)

What does "linear" mean?

"Let's not get too far off the subject here."

Dodging the subject because you don't
understand the subject.


>
> --dissertation on how an envelope detector works snipped--

Vain "editing".

>
>> Do you see how this applies to spectrum analyzers
>> and the human auditory system?
>
> Sure. But
>
> 1) It is possible -- if not practical -- to build a "detectorless" (in
> the nonlinear process sense) spectrum analyzer, and

Red herring.

>
> 2) None of it is even remotely significant to the subject at hand.

A repeat of your earlier dodging.

>
> Here it is again: the "beat" one hears when tuning a guitar or other
> instrument does *not* require any nonlinear process for its production.
> Period.

You didn't know a spectrum analyzer is nonlinear.
You didn't/don't know that a bolometer is nonlinear.
You wouldn't and don't know nonlinearity even when you
hear it.

>
> Isaac

You are a poseur.



Author: Jimmie D
Date: 06:26 10-07-07


"Ron Baker, Pluralitas!" <this@aint.me> wrote in message
news:4693037c$0$31221$4c368faf@roadrunner.com...
>
> "Dana" <raff242@yahoo.com> wrote in message
> news:80b7c$46906e83$944e306e$20475@STARBAND.NET... /> >>
>> "Ron Baker, Pluralitas!" <
this@aint.me> wrote in message
>> news:469064fd$0$16540$4c368faf@roadrunner.com...
>>>> Do you understand that a DSB signal *is* AM?
>>>
>>> So all the AM broadcasters are wasting money by
>>> generating a carrier?
>>
>> How did you jump to that conclusion.
>
> Is "DSBSC" DSB?
>

There have been attempts to remove the carrier but receivers could not be
manufatured at a reasonable price that would demodulate the signal with the
fidelity of an AM BCB signal. Probably could be done today but what would
you l do with all those AM rx that suddenly dont work when the transition is
made.



Author: Don Bowey
Date: 10:55 10-07-07

On 7/10/07 3:26 AM, in article 46935ee4$0$30624$4c368faf@roadrunner.com,
"Jimmie D" <GFENDER@carolina.rr.com> wrote:

>
> "Ron Baker, Pluralitas!" <this@aint.me> wrote in message
> news:4693037c$0$31221$4c368faf@roadrunner.com...
>>
>> "Dana" <raff242@yahoo.com> wrote in message
>> news:80b7c$46906e83$944e306e$20475@STARBAND.NET... /> >>>
>>> "Ron Baker, Pluralitas!" <
this@aint.me> wrote in message
>>> news:469064fd$0$16540$4c368faf@roadrunner.com...
>>>>> Do you understand that a DSB signal *is* AM?
>>>>
>>>> So all the AM broadcasters are wasting money by
>>>> generating a carrier?
>>>
>>> How did you jump to that conclusion.
>>
>> Is "DSBSC" DSB?

I see Jimmie talked all around your question.

I'll answer it AGAIN, though I'm still sure your only a troll.....

DSB says nothing about the carrier; DSBSC is still DSB.

You can have DSBSC (Suppressed Carrier), DSBRC (Reduced Carrier), and DSB
with Full Carrier. You can look up the abbreviation for the latter if you
need it.

Broadcast medium wave radio, slang term "AM Radio," is DSB with full
Carrier.

>>
>
> There have been attempts to remove the carrier but receivers could not be
> manufatured at a reasonable price that would demodulate the signal with the
> fidelity of an AM BCB signal. Probably could be done today but what would
> you l do with all those AM rx that suddenly dont work when the transition is
> made.
>
>


Author: Bob Myers
Date: 11:16 10-07-07


"Ron Baker, Pluralitas!" <this@aint.me> wrote in message
news:4693037c$0$31221$4c368faf@roadrunner.com...

>>> So all the AM broadcasters are wasting money by
>>> generating a carrier?
>>
>> How did you jump to that conclusion.
>
> Is "DSBSC" DSB?

Obviously, since it has both sidebands. What it's
missing, vs. "normal" AM, is the carrier.

Bob M.



Author: Ian Jackson
Date: 11:22 10-07-07

In message <C2B8EBE6.6EB5C%dbowey@comcast.net>, Don Bowey
<dbowey@comcast.net> writes
>On 7/10/07 3:26 AM, in article 46935ee4$0$30624$4c368faf@roadrunner.com,
>"Jimmie D" <GFENDER@carolina.rr.com> wrote:
>
>>
>> "Ron Baker, Pluralitas!" <this@aint.me> wrote in message
>> news:4693037c$0$31221$4c368faf@roadrunner.com...
>>>
>>> "Dana" <raff242@yahoo.com> wrote in message
>>> news:80b7c$46906e83$944e306e$20475@STARBAND.NET... /> >>>>
>>>> "Ron Baker, Pluralitas!" <
this@aint.me> wrote in
message
>>>> news:469064fd$0$16540$4c368faf@roadrunner.com...
>>>>>> Do you understand that a DSB signal *is* AM?
>>>>>
>>>>> So all the AM broadcasters are wasting money by
>>>>> generating a carrier?
>>>>
>>>> How did you jump to that conclusion.
>>>
>>> Is "DSBSC" DSB?
>
>I see Jimmie talked all around your question.
>
>I'll answer it AGAIN, though I'm still sure your only a troll.....
>
>DSB says nothing about the carrier; DSBSC is still DSB.
>
>You can have DSBSC (Suppressed Carrier), DSBRC (Reduced Carrier), and DSB
>with Full Carrier. You can look up the abbreviation for the latter if you
>need it.
>
>Broadcast medium wave radio, slang term "AM Radio," is DSB with full
>Carrier.
>
>>>
>>
>> There have been attempts to remove the carrier but receivers could not be
>> manufatured at a reasonable price that would demodulate the signal with the
>> fidelity of an AM BCB signal. Probably could be done today but what would
>> you l do with all those AM rx that suddenly dont work when the transition is
>> made.
>>
>>
>
Just out of interest....
http://www.vkham.com/vk8da/documents/ModesOfOperation.pdf
Ian.
--


Author: Dana
Date: 21:54 10-07-07


"Don Bowey" <dbowey@comcast.net> wrote in message
news:C2B8EBE6.6EB5C%dbowey@comcast.net...
> On 7/10/07 3:26 AM, in article 46935ee4$0$30624$4c368faf@roadrunner.com,
> "Jimmie D" <GFENDER@carolina.rr.com> wrote:
>
>>
>> "Ron Baker, Pluralitas!" <this@aint.me> wrote in message
>> news:4693037c$0$31221$4c368faf@roadrunner.com...
>>>
>>> "Dana" <raff242@yahoo.com> wrote in message
>>> news:80b7c$46906e83$944e306e$20475@STARBAND.NET... /> >>>>
>>>> "Ron Baker, Pluralitas!" <
this@aint.me> wrote in
message
>>>> news:469064fd$0$16540$4c368faf@roadrunner.com...
>>>>>> Do you understand that a DSB signal *is* AM?
>>>>>
>>>>> So all the AM broadcasters are wasting money by
>>>>> generating a carrier?
>>>>
>>>> How did you jump to that conclusion.
>>>
>>> Is "DSBSC" DSB?
>
> I see Jimmie talked all around your question.

Actually Jimmie gave a plausable reason to your statement/question that AM
broadcasters are wasting money by generating a carrier.
>
> I'll answer it AGAIN, though I'm still sure your only a troll.....
>
> DSB says nothing about the carrier; DSBSC is still DSB.

You still have to have a carrier to modulate.
>
> You can have DSBSC (Suppressed Carrier), DSBRC (Reduced Carrier), and DSB
> with Full Carrier. You can look up the abbreviation for the latter if you
> need it.

And you still need to modulate a carrier. So your statement/question that AM
broadcasters are wasting money by generating a carrier was illogical in the
context of this thread.
>
> Broadcast medium wave radio, slang term "AM Radio," is DSB with full
> Carrier.

So then you agree that the Broadcasters are not wasting money by generating
a carrier.
>
>>>
>>
>> There have been attempts to remove the carrier but receivers could not be
>> manufatured at a reasonable price that would demodulate the signal with
>> the
>> fidelity of an AM BCB signal. Probably could be done today but what would
>> you l do with all those AM rx that suddenly dont work when the transition
>> is
>> made.
>>
>>
>



Author: Don Bowey
Date: 23:40 10-07-07

On 7/10/07 6:54 PM, in article f368f$46943866$944e306e$3971@STARBAND.NET,
"Dana" <raff242@yahoo.com> wrote:

>
> "Don Bowey" <dbowey@comcast.net> wrote in message
> news:C2B8EBE6.6EB5C%dbowey@comcast.net...
>> On 7/10/07 3:26 AM, in article 46935ee4$0$30624$4c368faf@roadrunner.com,
>> "Jimmie D" <GFENDER@carolina.rr.com> wrote:
>>
>>>
>>> "Ron Baker, Pluralitas!" <this@aint.me> wrote in message
>>> news:4693037c$0$31221$4c368faf@roadrunner.com...
>>>>
>>>> "Dana" <raff242@yahoo.com> wrote in message
>>>> news:80b7c$46906e83$944e306e$20475@STARBAND.NET... /> >>>>>
>>>>> "Ron Baker, Pluralitas!" <
this@aint.me> wrote in
message
>>>>> news:469064fd$0$16540$4c368faf@roadrunner.com...
>>>>>>> Do you understand that a DSB signal *is* AM?
>>>>>>
>>>>>> So all the AM broadcasters are wasting money by
>>>>>> generating a carrier?
>>>>>
>>>>> How did you jump to that conclusion.
>>>>
>>>> Is "DSBSC" DSB?
>>
>> I see Jimmie talked all around your question.
>
> Actually Jimmie gave a plausable reason to your statement/question that AM
> broadcasters are wasting money by generating a carrier.

Actually, he talked about the topic without answering the question asked by
the OP.

>>
>> I'll answer it AGAIN, though I'm still sure your only a troll.....
>>
>> DSB says nothing about the carrier; DSBSC is still DSB.
>
> You still have to have a carrier to modulate.

Obviously a reference carrier is required..... So what's your point? "DSB"
tells us NOTHING about the carrier; is it suppressed, reduced, or full in
the transmitted signal?

Maybe you should read an entire post before replying.

>>
>> You can have DSBSC (Suppressed Carrier), DSBRC (Reduced Carrier), and DSB
>> with Full Carrier. You can look up the abbreviation for the latter if you
>> need it.
>
> And you still need to modulate a carrier. So your statement/question that AM
> broadcasters are wasting money by generating a carrier was illogical in the
> context of this thread.

I did not ever say AM broadcasters are wasting money by generating a
carrier. Get your story straight.

You need a reference carrier for generating sidebands, but you do not "need"
to transmit the carrier unless it's required by a specific service.

>>
>> Broadcast medium wave radio, slang term "AM Radio," is DSB with full
>> Carrier.
>
> So then you agree that the Broadcasters are not wasting money by generating
> a carrier.

Read the sentence just above your above sentence. A transmitted, full
carrier is required for the broadcast service. Other services don't require
it.
>>
>>>>
>>>
>>> There have been attempts to remove the carrier but receivers could not be
>>> manufatured at a reasonable price that would demodulate the signal with
>>> the
>>> fidelity of an AM BCB signal. Probably could be done today but what would
>>> you l do with all those AM rx that suddenly dont work when the transition
>>> is
>>> made.
>>>
>>>
>>
>
>


Author: isw
Date: 01:41 11-07-07

In article <46931ec3$0$4718$4c368faf@roadrunner.com>,
"Ron Baker, Pluralitas!" <this@aint.me> wrote:

> "isw" <isw@witzend.com> wrote in message
> news:isw-97799B.10580608072007@newsgroups.comcast.net...
> > In article <46910fe5$0$8925$4c368faf@roadrunner.com>,
> > "Ron Baker, Pluralitas!" <this@aint.me> wrote:
> >
> >> "isw" <isw@witzend.com> wrote in message
> >> news:isw-664E24.21491207072007@newsgroups.comcast.net...
> >> > In article <468fe7df$0$16560$4c368faf@roadrunner.com>,
> >> > "Ron Baker, Pluralitas!" <this@aint.me> wrote:

> > Here it is again: the "beat" one hears when tuning a guitar or other
> > instrument does *not* require any nonlinear process for its production.
> > Period.
>
> You didn't know a spectrum analyzer is nonlinear.
> You didn't/don't know that a bolometer is nonlinear.
> You wouldn't and don't know nonlinearity even when you
> hear it.

And you still didn't address the original point. Why not?

Isaac

Author: isw
Date: 01:59 11-07-07

In article <46935ee4$0$30624$4c368faf@roadrunner.com>,
"Jimmie D" <GFENDER@carolina.rr.com> wrote:

> "Ron Baker, Pluralitas!" <this@aint.me> wrote in message
> news:4693037c$0$31221$4c368faf@roadrunner.com...
> >
> > "Dana" <raff242@yahoo.com> wrote in message
> > news:80b7c$46906e83$944e306e$20475@STARBAND.NET... /> > >>
> >> "Ron Baker, Pluralitas!" <
this@aint.me> wrote in message
> >> news:469064fd$0$16540$4c368faf@roadrunner.com...
> >>>> Do you understand that a DSB signal *is* AM?
> >>>
> >>> So all the AM broadcasters are wasting money by
> >>> generating a carrier?
> >>
> >> How did you jump to that conclusion.
> >
> > Is "DSBSC" DSB?
> >
>
> There have been attempts to remove the carrier but receivers could not be
> manufatured at a reasonable price that would demodulate the signal with the
> fidelity of an AM BCB signal. Probably could be done today but what would
> you l do with all those AM rx that suddenly dont work when the transition is
> made.

There's no advantage to DSB-SC that SSB-SC doesn't have and several that
SSB-SC alone has. Getting rid of one of the redundant sets of sidebands
halves the required bandwidth, for one. Also, if the two sideband sets
of DSB-SC experience differing phase alteration due to propagation
effects (not too uncommon), the signal can become unintelligible; that
effect is minimized with SSB-SC.

If all broadcasters used SSB-SC and precision frequency control (easy
and inexpensive these days) then SSB-SC receivers are pretty easy. But
that doesn't solve the problem of all those AM receivers...

Things seem to be moving in the direction of digital modulation and even
more complex receivers; whether that's a Good Thing or not, I'm not sure.

Isaac

Date: 11:32 13-07-07

On Jul 1, 11:11 am, Jeff Liebermann <je...@cruzio.com> wrote:
> John Smith I <assemblywiz...@gmail.com> hath wroth:
>
> >RHF wrote:
> > > ...
> >> Because "Radium" Touched Them With A Thirst
> >> For Knowledge And A Quest For Answers.
> >> ...
> >I don't know, according to any instructor I have ever had respect for:
> >"There are NO stupid questions, only stupid people who are afraid to ask
> >questions."
>
> I beg to differ. My favorite mentor/instructor/employer had a
> different philosophy regarding questions and answers. His line was
> something like "If you don't understand the problem, no solution is
> possible". His method was to concentrate on understanding the
> problem, refining the corresponding questions, and only then
> concentrating on finding the answer. I would spend much more time
> thinking about "what problem am I trying to solve" instead of
> blundering prematurely toward some potentially irrelevant solution.
>
> My problem with the original question is that it fails to associate
> itself with anything recognizable as a real problem to solve or a
> theory to expound. In my never humble opinion, if there was a
> question under all that rubbish, it was quite well hidden and severely
> muddled. He also introduced a substantial number of "facts" that
> varied from irrelevant to incoherent to just plain wrong. The problem
> for us in not in finding the answer, but in decoding the question.
>
> There may not be any stupid questions, but there seem to be a
> substantial number of marginal people asking questions. I answer some
> techy questions in alt.internet.wireless. What I see, all too often,
> are people that seem to think that no effort on their part is
> necessary to obtain an answer. They exert no effort to read the FAQ,
> no effort to supply what problem they are trying to solve, and no
> effort to supply what they have to work with. In this case, Mr Radium
> has either exerted no effort to compose his question in a form that
> can be answered, or if there was such an effort, it has failed
> miserably. He couldn't even find a suitable collection of newsgroups
> for his question.
>
> There may not be any stupid questions, but there certainly are
> questions not worth the time attempting to answer. If Mr Radium had
> left the question at the subject line:
> "AM electromagnetic waves: 20 KHz modulation frequency on
> an astronomically-low carrier frequency"
> the question would have been easy to answer, as several people have
> done. However, those that answered and I all did the same thing. We
> extracted from the word salad question what we thought was something
> resembling a coherent question, and ignored the rest of the rubbish.
> In other words, we did the necessary simplification and problem
> reduction, and discarded the bulk of the incoherent residue. There
> may not be any stupid questions, but if you bury it under a sufficient
> number of words, it may closely resemble a stupid question.
>
> >Depends ... I guess.
> >JS
>
> Well, let's see:
>
<http://groups.google.com/groups?as_q=%22guess%28tm%29%22&as_uauthors=...>;
> 533 guesses, out of about 16,000 postings, which I guess(tm) isn't all
> that bad.
>
> --
> Jeff Liebermann je...@cruzio.com
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060http://802.11junk.com
> Skype: JeffLiebermann AE6KS 831-336-2558

thankyou, for the wonderfully varied responses.

here's my question?

as one who simply asks the questions!

can fm waves ( any kind) PIGGY BACK ON AM WAVES?

THE IMPLICATIONS ARE FAR REACHING!!!!!!!!!

REMEBER AS OUR GREAT ANCESTORS SO ELOCENTLY PUT IT (PARAPHRASED)

WHEN CONSIDERING THE LIGHT BULB

" I FOUND 2000 NEW WAYS OF THINKING"

BUT THIS GREAT MAN DIDNT FINNISH UNTIL THE GOAL WAS REACHED

ADMIRABLE QUALITIES.

personally speaking, I have no formal or imformal education that can
match the depths of this scientific quorum.

I do have a vision

I hope to find new ways every day of connecting so i can get to the
beaches where the waves and the people think outside the box of normal
surfing and envision a whole new world metaphoricaly speaking.

Im a beach boys fan!!!!!!!!


Author: Jeff Liebermann
Date: 12:53 13-07-07

shawn.cormican@gmail.com hath wroth:

>thankyou, for the wonderfully varied responses.

Please learn to operate a text editor and kindly trim the surplus
quotes from your ranting. I can't stand to read my own stuff twice.

>can fm waves ( any kind) PIGGY BACK ON AM WAVES?

Sure. It's called QAM (quadrature amplitude muddlation). The
quadrature part is actually PM (phase modulation), which is a form of
FM (freak modulation). The amplitude also varies at the same time.
Look for the constellation diagrams. Which one is a pig on which back
is an open question.

>personally speaking, I have no formal or imformal education that can
>match the depths of this scientific quorum.

Yeah, it shows.

>I do have a vision

Your vision is not 20-20. I suggest corrective glasses.

>I hope to find new ways every day of connecting so i can get to the
>beaches where the waves and the people think outside the box of normal
>surfing and envision a whole new world metaphoricaly speaking.

Never mind thinking outside the box. Work on thinking in the first
place. Once you master that, you can worry whether it works better
inside or outside a box.

I guess it's true. Too much RF, or too much beach sun, causes
insanity.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Author: John Fields
Date: 07:42 14-07-07

On Fri, 13 Jul 2007 09:53:21 -0700, Jeff Liebermann
<jeffl@cruzio.com> wrote:

>shawn.cormican@gmail.com hath wroth:
>
>>thankyou, for the wonderfully varied responses.
>
>Please learn to operate a text editor and kindly trim the surplus
>quotes from your ranting. I can't stand to read my own stuff twice.

---
I can barely stomach it the _first_ time around! ;)


--
JF

Author: Jeff Liebermann
Date: 11:56 14-07-07

John Fields <jfields@austininstruments.com> hath wroth:

>On Fri, 13 Jul 2007 09:53:21 -0700, Jeff Liebermann
><jeffl@cruzio.com> wrote:
>
>>shawn.cormican@gmail.com hath wroth:
>>
>>>thankyou, for the wonderfully varied responses.

>>Please learn to operate a text editor and kindly trim the surplus
>>quotes from your ranting. I can't stand to read my own stuff twice.

>I can barely stomach it the _first_ time around! ;)

My rants have been accused of being all manner of things. However,
this is the first time they've been accused of being indigestible. If
your stomach can't take it, and you feel the need to regurgitate an
apparently involuntary one line response, I can offer a suitable
therapeutic regime. If you read my writings, rants, stories, humor,
and poetry in much smaller portions, you will eventually find my stuff
more agreeable. Given sufficient time, you will develop a tolerance
for my stuff. Incidentally, my writings are rather dry and might
require a few grains of salt to be considered tasteful.

If only they would pay my time,
to write this stuff in verse and rhyme.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

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