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Old June 30th 07, 09:16 PM posted to sci.electronics.basics,rec.radio.amateur.antenna,alt.cellular.cingular,alt.internet.wireless
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Default AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency

On Jun 30, 10:14 am, "Porgy Tirebiter" wrote:
- "Radium" is a well known "Troll".
- When he runs low/out of meds and tin foil he will
- post this techo-babble crap all over usenet.
- Just add him to your killfile list.
- "Radium" is a "Throw-away"....a complete waste of time......

PT - Then why waste your time replying to his posts ?

IMHO - In another life "Radium" would have made
a great High School Science Teacher :
Who's Students when on to do great things with
their lives :
Because "Radium" Touched Them With A Thirst
For Knowledge And A Quest For Answers.

-but- These NewsGroups are NOT a High School
Science Class -and- "Radium" is just being 'radium'.
http://en.wikipedia.org/wiki/Radium

-alas- Our "Radium's" Half-Life of Readable Interest
http://en.wikipedia.org/wiki/Half-life
is at best about 16.04 Seconds ~ RHF
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Old June 30th 07, 09:25 PM posted to sci.electronics.basics,rec.radio.shortwave,rec.radio.amateur.antenna,alt.cellular.cingular,alt.internet.wireless
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Default AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency

In rec.radio.amateur.antenna Radium wrote:
On Jun 30, 3:32 am, "Mike Kaliski" wrote:


It is not possible to modulate a carrier frequency at a frequency higher
than the carrier frequency.


Why not?


I am getting conflicting answers. Some say it's possible to modulate a
carrier frequency at a frequency higher than the carrier frequency,
others say it isn't.


Who is right?


The defining equations, you blithering idtiot.

Here they are for the last time:

http://ccrma.stanford.edu/~jos/mdft/...lation_AM.html


--
Jim Pennino

Remove .spam.sux to reply.
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Old June 30th 07, 09:25 PM posted to sci.electronics.basics,rec.radio.shortwave,rec.radio.amateur.antenna,alt.cellular.cingular,alt.internet.wireless
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Default (OT) : Radium - In Another Life You Would Have Made A Great High School Science Teacher

RADIUM,

IMHO - In another life "Radium" you would have
made a great High School Science Teacher :
Who's Students when on to do great things with
their lives :
Because You "Radium" Touched Them With A
Thirst For Knowledge And A Quest For Answers.

-but- These NewsGroups are NOT a High School
Science Class -and- "Radium" you are just being
'radium'. = http://en.wikipedia.org/wiki/Radium
decaying into a gas and dispersing into nothingness.
http://en.wikipedia.org/wiki/Radon

-alas- "Radium" Your Half-Life of Readable Interest
http://en.wikipedia.org/wiki/Half-life
is at best about 16.04 Seconds ~ RHF
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Old June 30th 07, 09:34 PM posted to sci.electronics.basics,rec.radio.amateur.antenna,alt.cellular.cingular,alt.internet.wireless
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Default AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-lowcarrier frequency

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."

Depends ... I guess.

JS
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Old June 30th 07, 09:38 PM posted to sci.electronics.basics,rec.radio.shortwave,rec.radio.amateur.antenna,alt.cellular.cingular,alt.internet.wireless
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Default AM electromagnetic waves: 20 KHz modulation frequency on anastronomically-low carrier frequency

On 6/30/07 12:46 PM, in article
, "Radium"
wrote:

On Jun 30, 3:32 am, "Mike Kaliski" wrote:

It is not possible to modulate a carrier frequency at a frequency higher
than the carrier frequency.


Why not?

I am getting conflicting answers. Some say it's possible to modulate a
carrier frequency at a frequency higher than the carrier frequency,
others say it isn't.


Partly it's because you formulate **** poor questions.


Who is right?


Neither if stated as an "absolute rule," a.k.a. a Universal Generalization.
It depends on what you want as a result. However, IMHO opinion, I believe
it is best to have the Carrier at a higher frequency than the modulating
frequency.

If you are amplitude modulating a Carrier with a voice band signal, then it
is mandatory, for a reasonable result, that the Carrier have a much higher
frequency than the modulating frequency.

If you are AM modulating (a.k.a. RF mixing or converting) two signals for
the purpose of creating sum and difference "Carriers" in, for example, a
synthesizer, you could use the low frequency to "modulate" the high
frequency frequency, but I donąt recommend it unless some special effect is
desired.


Start with the question of what is it you wish to accomplish then ask real
questions, not some far-out hypothetical drivel.






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Old June 30th 07, 09:44 PM posted to sci.electronics.basics,rec.radio.amateur.antenna,alt.cellular.cingular,alt.internet.wireless
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Default AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency

On Jun 30, 1:38 pm, Don Bowey wrote:
On 6/30/07 12:46 PM, in article
. com, "Radium"

wrote:
On Jun 30, 3:32 am, "Mike Kaliski" wrote:


It is not possible to modulate a carrier frequency at a frequency higher
than the carrier frequency.


Why not?


I am getting conflicting answers. Some say it's possible to modulate a
carrier frequency at a frequency higher than the carrier frequency,
others say it isn't.


Partly it's because you formulate **** poor questions.



Who is right?


Neither if stated as an "absolute rule," a.k.a. a Universal Generalization.
It depends on what you want as a result. However, IMHO opinion, I believe
it is best to have the Carrier at a higher frequency than the modulating
frequency.

If you are amplitude modulating a Carrier with a voice band signal, then it
is mandatory, for a reasonable result, that the Carrier have a much higher
frequency than the modulating frequency.

If you are AM modulating (a.k.a. RF mixing or converting) two signals for
the purpose of creating sum and difference "Carriers" in, for example, a
synthesizer, you could use the low frequency to "modulate" the high
frequency frequency, but I donąt recommend it unless some special effect is
desired.

Start with the question of what is it you wish to accomplish then ask real
questions, not some far-out hypothetical drivel.


.

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Old June 30th 07, 09:54 PM posted to sci.electronics.basics,rec.radio.shortwave,rec.radio.amateur.antenna,alt.cellular.cingular,alt.internet.wireless
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Default AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency


"Radium" wrote in message
oups.com...
On Jun 30, 3:32 am, "Mike Kaliski" wrote:

It is not possible to modulate a carrier frequency at a frequency higher
than the carrier frequency.


Why not?

I am getting conflicting answers. Some say it's possible to modulate a
carrier frequency at a frequency higher than the carrier frequency,
others say it isn't.

Who is right?

Radium

Me

Read my entire earlier reply. Then go to the library and spend several years
reading through the electronics section with particular emphasis on the
origins of electrical technology and early wireless. Then take a technical
biased university course incorporating logic and critical analysis and all
will become clear.

Without a basic knowledge of the subject, you are unable to make any form of
critical judgement as to the accuracy or correctness of what people are
telling you and all your questions become valueless because you do not have
the nous to evaluate the answers you receive.

Start with the basics and then try working up from there. Many inadvisable
things are technically possible, putting a dead short across the mains will
generate a pretty good example of electromagnetic pulse, but it is far
better to use a capacitive discharge circuit to do the same job. You could
try modulating carriers at all different sorts of frequencies to generate
harmonics, far better to use a square wave generator. You get the idea.

Regards

Mike G0ULI


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Old July 1st 07, 03:01 AM posted to sci.electronics.basics,rec.radio.shortwave,rec.radio.amateur.antenna,alt.cellular.cingular,alt.internet.wireless
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Default AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency

On Jun 30, 3:46 pm, Jeff Liebermann wrote:

With AM, it's ALWAYS the high frequency
that acts as the carrier
and the lower that acts as the modulation.


In AM, isn't the carrier the signal which always maintains a constant
frequency and only varies by amplitude?

If a carrier signal varies by anything other than just amplitude, then
it isn't AM. Right?

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Old July 1st 07, 03:31 AM posted to sci.electronics.basics,rec.radio.shortwave,rec.radio.amateur.antenna,alt.cellular.cingular,alt.internet.wireless
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Default AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-lowcarrier frequency

Radium wrote:

...
If a carrier signal varies by anything other than just amplitude, then
it isn't AM. Right?


Let logic be your guide, again. As was pointed out earlier, the voice
freqs which modulate the carrier will cause a variance in freq (a small
fm component.)

In fm, it is not unusual for a small "amplitude modulation" to be
generated, as the varying/spanning of freq(s) is caused by the
modulation, some changes in fm carrier can be generated.

In an imperfect world, nothing is "perfect."

Regards,
JS
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Old July 1st 07, 03:43 AM posted to sci.electronics.basics,rec.radio.shortwave,rec.radio.amateur.antenna,alt.cellular.cingular,alt.internet.wireless
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Default AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency

Radium hath wroth:

On Jun 30, 3:46 pm, Jeff Liebermann wrote:

With AM, it's ALWAYS the high frequency
that acts as the carrier
and the lower that acts as the modulation.


In AM, isn't the carrier the signal which always maintains a constant
frequency and only varies by amplitude?


You really are clueless. The carrier does NOT vary in amplitude. If
it did, that would be modulating the carrier, which is the job of the
modulator, not whatever is producing the carrier. You could have two
modulators in series, that would make the circuit overly complicated.
Please re-read my highly simplified previous explanation about the
symmetry of the AM multiplier (mixer) input ports until it's absorbed
and understood by your porous brain.

Incidentally, the reason I keep using the term "multiplier (mixer)" is
to avoid confusion with a harmonic multiplier. An AM modulator is a
mixer, not a harmonic multiplier.

Also, the carrier might remain constant frequency, for a given FCC
channel assignment, but the modulation is all over the place. For
example, your voice goes from 300 to 3000Hz, all of which is fed to
the modulator for digestion.

Conventional TV is VSB (visidual side band) which is a form of AM with
one of the two side bands partially removed, usually by filtering.
There's a carrier 1.25MHz offset for the video, another carrier 4.5Mhz
offset for the audio, and whatever else they can throw in for low
speed data. Two more more carriers are required for TV+audio.

If you want to get really high-techy, the new digital modes (DRM,
iBiquity, HD Radio, etc) all have multiple carriers, each of which is
modulated individually. Same with various OFDM modes, which have
multiple carriers, individually modulated and positioned orthogonally
from each other to prevent mutual interference from adjacent modulated
carriers.

If a carrier signal varies by anything other than just amplitude, then
it isn't AM. Right?


Wrong. The carrier can also vary, such as in a sweep generator or
jammer. It's not commonly done but it's possible. Want to obliterate
the entire AM broadcast band? No problem. Just sweep the carrier
from 530KHz to 1650KHz, while modulating the 300 to 3000Hz audio with
a rendition of your incoherent ranting.

By the way, you're welcome.


--
Jeff Liebermann
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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