AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-lowcarrier frequency

Radium wrote:

> ...
> Is it mathematically-possible to carry a modulator signal [in this
> case, a pure-sine-wave-tone] with a frequency of 20 KHz and an
> amplitude of 1-watt-per-meter-squared on a AM carrier signal whose

The 20 Khz is obviously NOT an audio tone, but exists as VLF, what you
are terming "modulation" is actually a mixing of carriers then ... and
the problem with your question ONLY BEGINS there!

JS

---

› See More: AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-lowcarrier frequency

Radium wrote:

WTF are you thinking when you describe the 20 Khz signal as, "a
pure-sine-wave-tone] with a frequency of 20 KHz and an
amplitude of 1-watt-per-meter-squared"

One square meter of copper wire squared, a squared meter of modulation
xfrmr ... ?

Your question sounds like one of a high school physics student
attempting to ask a seemingly logical--yet complex question, and of no
real world value.

Your ability at obfuscation is only mundane ...

If what you say is true, you have an interest, what is the purpose of
your question?

JS

On 6/29/07 9:03 PM, in article
[email protected], "Radium"
<[email protected]> wrote:

> On Jun 29, 8:08 pm, John Smith I <[email protected]> wrote:
>
>> The 20 Khz is obviously NOT an audio tone,
>
> Yes it is. 20 KHz is the highest audible frequency. Humans hear from
> 20 to 20,000 Hz. No offense but WTF are you thinking??
>
>> but exists as VLF, what you
>> are terming "modulation" is actually a mixing of carriers then ... and
>> the problem with your question ONLY BEGINS there!
>
> A carrier wave is modulated by the modulator wave. On most AM
> stations, the modulator wave consists of the voice of someone
> speaking.
>
> Most AM stations have carrier frequencies in the medium wave band - in
> the range of 520,000 to 1,160,000 cycles every 1 second.
>
> In the case I am describing, the modulator wave is a 20 KHz pure sine-
> wave tone on a carrier frequency of 10^-(1,000,000,000-to-the-
> power-10^1,000,000,000) nanocycle every 10^1,000,000,000-to-the-
> power-10^1,000,000,000 giga-eons. Is this scenario mathematically-
> possible? If not, then why??
>

No, it's not possible. No planetary system will exist for that span of
time.

Now will you go away?

On Jun 29, 9:15 pm, John Smith I <[email protected]> wrote:

> Radium wrote:
>
> WTF are you thinking when you describe the 20 Khz signal as, "a
> pure-sine-wave-tone] with a frequency of 20 KHz and an
> amplitude of 1-watt-per-meter-squared"
>
> One square meter of copper wire squared, a squared meter of modulation
> xfrmr ... ?

Sorry that should be 1 X [10^-6] Watts-per-m^2

http://www.glenbrook.k12.il.us/GBSSC...nd/u11l2b.html

1 X [10^-6] Watts-per-m^2 is about the loudness of a "normal
conversation" according to the above link.

F-------------------king typos!!!!!!!!!!

>
> Your question sounds like one of a high school physics student
> attempting to ask a seemingly logical--yet complex question, and of no
> real world value.
>
> Your ability at obfuscation is only mundane ...
>
> If what you say is true, you have an interest, what is the purpose of
> your question?

My basic question is if I have an AM receiver which receives signals
on a carrier frequency of Fc, is it mathematically-possible for me to
receive a modulator signal -- on that station -- of a frequency higher
than Fc? If not, then why? If not, then how are the submarines which
use ELFs [Extremely Low carrier Frequencies around 3 to 30 Hz] able to
perform voice communications?

I just stretched the question out to astronomical extremes. I have a
habit of doing that.

On 6/29/07 9:30 PM, in article
[email protected], "Radium"
<[email protected]> wrote:

> On Jun 29, 9:15 pm, John Smith I <[email protected]> wrote:
>
>> Radium wrote:
>>
>> WTF are you thinking when you describe the 20 Khz signal as, "a
>> pure-sine-wave-tone] with a frequency of 20 KHz and an
>> amplitude of 1-watt-per-meter-squared"
>>
>> One square meter of copper wire squared, a squared meter of modulation
>> xfrmr ... ?
>
> Sorry that should be 1 X [10^-6] Watts-per-m^2
>
> http://www.glenbrook.k12.il.us/GBSSC...nd/u11l2b.html
>
> 1 X [10^-6] Watts-per-m^2 is about the loudness of a "normal
> conversation" according to the above link.
>
> F-------------------king typos!!!!!!!!!!
>
>>
>> Your question sounds like one of a high school physics student
>> attempting to ask a seemingly logical--yet complex question, and of no
>> real world value.
>>
>> Your ability at obfuscation is only mundane ...
>>
>> If what you say is true, you have an interest, what is the purpose of
>> your question?
>
> My basic question is if I have an AM receiver which receives signals
> on a carrier frequency of Fc, is it mathematically-possible for me to
> receive a modulator signal -- on that station -- of a frequency higher
> than Fc? If not, then why?

What is the design bandwidth of the "fixed frequency" receiver?

When you say "modulator signal" do you mean a sideband of the transmitted
signal, or do you mean at least one sideband and the Carrier, or do you mean
the Carrier and both of it's sidebands?

It would be good if you would attempt to understand AM modulation, and
generally some of the factors of receiver design.

> If not, then how are the submarines which
> use ELFs [Extremely Low carrier Frequencies around 3 to 30 Hz] able to
> perform voice communications?

Why do you believe they use voice communications on the ELF system?

>
> I just stretched the question out to astronomical extremes. I have a
> habit of doing that.

You have a habit of appearing to be an idiot each time you do it.

"Radium" <[email protected]> wrote in message
news:[email protected]...
> My basic question is if I have an AM receiver which receives signals
> on a carrier frequency of Fc, is it mathematically-possible for me to
> receive a modulator signal -- on that station -- of a frequency higher
> than Fc? If not, then why? If not, then how are the submarines which
> use ELFs [Extremely Low carrier Frequencies around 3 to 30 Hz] able to
> perform voice communications?
>
> I just stretched the question out to astronomical extremes. I have a
> habit of doing that.

Why not simply ask the question you mean to ask, then, rather
than the absurd numbers you put in the original version of this
(and which you then expect everyone to work through, just to
see what the hell you might be talking about)?

The answer to the question you seem to be asking is obvious
if you simply work through the mathematics of what is going on
in amplitude modulation. So why not simply do that, and not
ask such incredibly obtuse questions?

One hint: the ELF submarine communications to which you refer
are NOT carrying voice communications, but very low-rate
CW ("Morse code," if you want to think of it that way) signalling.

Bob M.

On Jun 29, 9:24 pm, Don Bowey <[email protected]> wrote:
> On 6/29/07 9:03 PM, in article
> [email protected], "Radium"
>
>
>
>
>
> <[email protected]> wrote:
> > On Jun 29, 8:08 pm, John Smith I <[email protected]> wrote:
>
> >> The 20 Khz is obviously NOT an audio tone,
>
> > Yes it is. 20 KHz is the highest audible frequency. Humans hear from
> > 20 to 20,000 Hz. No offense but WTF are you thinking??
>
> >> but exists as VLF, what you
> >> are terming "modulation" is actually a mixing of carriers then ... and
> >> the problem with your question ONLY BEGINS there!
>
> > A carrier wave is modulated by the modulator wave. On most AM
> > stations, the modulator wave consists of the voice of someone
> > speaking.
>
> > Most AM stations have carrier frequencies in the medium wave band - in
> > the range of 520,000 to 1,160,000 cycles every 1 second.
>
> > In the case I am describing, the modulator wave is a 20 KHz pure sine-
> > wave tone on a carrier frequency of 10^-(1,000,000,000-to-the-
> > power-10^1,000,000,000) nanocycle every 10^1,000,000,000-to-the-
> > power-10^1,000,000,000 giga-eons. Is this scenario mathematically-
> > possible? If not, then why??
>
> No, it's not possible. No planetary system will exist for that span of
> time.
>
> Now will you go away?- Hide quoted text -
>
> - Show quoted text -

.

"Radium" <[email protected]> wrote in message
news:[email protected]...
> On Jun 29, 9:15 pm, John Smith I <[email protected]> wrote:
>
> > Radium wrote:
> >
> > WTF are you thinking when you describe the 20 Khz signal as, "a
> > pure-sine-wave-tone] with a frequency of 20 KHz and an
> > amplitude of 1-watt-per-meter-squared"
> >
> > One square meter of copper wire squared, a squared meter of modulation
> > xfrmr ... ?
>
> Sorry that should be 1 X [10^-6] Watts-per-m^2
>
> http://www.glenbrook.k12.il.us/GBSSC...nd/u11l2b.html
>
> 1 X [10^-6] Watts-per-m^2 is about the loudness of a "normal
> conversation" according to the above link.
>
> F-------------------king typos!!!!!!!!!!
>
> >
> > Your question sounds like one of a high school physics student
> > attempting to ask a seemingly logical--yet complex question, and of no
> > real world value.
> >
> > Your ability at obfuscation is only mundane ...
> >
> > If what you say is true, you have an interest, what is the purpose of
> > your question?
>
> My basic question is if I have an AM receiver which receives signals
> on a carrier frequency of Fc, is it mathematically-possible for me to
> receive a modulator signal -- on that station -- of a frequency higher
> than Fc? If not, then why? If not, then how are the submarines which
> use ELFs [Extremely Low carrier Frequencies around 3 to 30 Hz] able to
> perform voice communications?
>
> I just stretched the question out to astronomical extremes. I have a
> habit of doing that.
>
Radium

It is not possible to modulate a carrier frequency at a frequency higher
than the carrier frequency. It wouldn't be a carrier frequency then, the
higher frequency would become the carrier frequency by default.

ELF communications are carried out at very slow data rates, only a few
characters per hour at best. Normal demodulation techniques are useless at
these frequencies and messages are received by what amounts to comparing the
noise levels on a given very narrow frequency band over long periods.
Computers are easily capable of performing this task. Messages are generally
sent as 3 character codes which are then looked up in a code book to read
the full text of the message. Each message can take half an hour or more to
send. Only a very limited set of pre arranged messages can be passed but
this is enough to tell a sub to approach the surface and establish line of
sight comms direct to a satellite, when more detailed messages can be passed
securely and at high speeds on higher frequencies (i.e voice and data
communications). Voice comms cannot be passed at VLF or ELF frequencies.

Nuclear subs are extremely autonomous. There is no quick way to establish
communications once they have left port and submerged.

It is possible to communicate at a base band frequency of 0Hz. This is what
happens when you talk down a hard wired telephone or intercom. At a
telephone exchange (switching centre), the signals from each line are
modulated onto a higher frequency for onward transmission down a trunk wire
cable or fibre optic cable. The multiplexed high frequency modulated signals
are down converted back to audio frequencies once they reach the intended
destination.

It is also possible to transmit this signal through the air (at incredibly
low efficiencies and powers). The miles of cables snaking through the
trenches in World War One were so long that messages could be intercepted by
the enemy listening in without any direct connection to the system. A good
ground connection and half a mile of wire rolled out across no mans land was
sufficient to pick up the signals from the other side. Systems were also
discovered which employed two widely separated ground connections and
avoided the need to send men out on a suicide mission to carry wires towards
the enemy trenches.

Mike G0ULI

["Followup-To:" header set to sci.electronics.basics.]
On 2007-06-30, John Smith I <[email protected]> wrote:
> Radium wrote:
>
> WTF are you thinking when you describe the 20 Khz signal as, "a
> pure-sine-wave-tone] with a frequency of 20 KHz and an
> amplitude of 1-watt-per-meter-squared"

Candela

Admittedly an odd unit to use for radiation at that frequency.

Bye.
Jasen

"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......

On Jun 30, 3:32 am, "Mike Kaliski" <[email protected]> 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 wrote:

> ...
> 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:

Use simple logic, you can modulate a dc (0 Hz) with higher freq (voice),
(hint, your telephone line is an example) right?

However, when you get into RF--possible, usable, desirable are seperate
and distinct things.

Again, with simple logic, modulating a 30 CPS signal with limited voice
freq (say 5K wide) is going to create a LOT of harmonics and mixed
signals, ain't it? Suggesting a very wide band receiver would be needed
to begin with ... in my humble opinion, and for various reasons, NO, it
is NOT possible ...

Regards,
JS

On Jun 30, 3:32 am, "Mike Kaliski" <[email protected]> wrote:
> "Radium" <[email protected]> wrote in message
>
> news:[email protected]...
>
>
>
> > On Jun 29, 9:15 pm, John Smith I <[email protected]> wrote:
>
> > > Radium wrote:
>
> > > WTF are you thinking when you describe the 20 Khz signal as, "a
> > > pure-sine-wave-tone] with a frequency of 20 KHz and an
> > > amplitude of 1-watt-per-meter-squared"
>
> > > One square meter of copper wire squared, a squared meter of modulation
> > > xfrmr ... ?
>
> > Sorry that should be 1 X [10^-6] Watts-per-m^2
>
> >http://www.glenbrook.k12.il.us/GBSSC...nd/u11l2b.html
>
> > 1 X [10^-6] Watts-per-m^2 is about the loudness of a "normal
> > conversation" according to the above link.
>
> > F-------------------king typos!!!!!!!!!!
>
> > > Your question sounds like one of a high school physics student
> > > attempting to ask a seemingly logical--yet complex question, and of no
> > > real world value.
>
> > > Your ability at obfuscation is only mundane ...
>
> > > If what you say is true, you have an interest, what is the purpose of
> > > your question?
>
> > My basic question is if I have an AM receiver which receives signals
> > on a carrier frequency of Fc, is it mathematically-possible for me to
> > receive a modulator signal -- on that station -- of a frequency higher
> > than Fc? If not, then why? If not, then how are the submarines which
> > use ELFs [Extremely Low carrier Frequencies around 3 to 30 Hz] able to
> > perform voice communications?
>
> > I just stretched the question out to astronomical extremes. I have a
> > habit of doing that.
>
> Radium
>
> It is not possible to modulate a carrier frequency at a frequency higher
> than the carrier frequency. It wouldn't be a carrier frequency then, the
> higher frequency would become the carrier frequency by default.
>
> ELF communications are carried out at very slow data rates, only a few
> characters per hour at best. Normal demodulation techniques are useless at
> these frequencies and messages are received by what amounts to comparing the
> noise levels on a given very narrow frequency band over long periods.
> Computers are easily capable of performing this task. Messages are generally
> sent as 3 character codes which are then looked up in a code book to read
> the full text of the message. Each message can take half an hour or more to
> send. Only a very limited set of pre arranged messages can be passed but
> this is enough to tell a sub to approach the surface and establish line of
> sight comms direct to a satellite, when more detailed messages can be passed
> securely and at high speeds on higher frequencies (i.e voice and data
> communications). Voice comms cannot be passed at VLF or ELF frequencies.
>
> Nuclear subs are extremely autonomous. There is no quick way to establish
> communications once they have left port and submerged.
>
> It is possible to communicate at a base band frequency of 0Hz. This is what
> happens when you talk down a hard wired telephone or intercom. At a
> telephone exchange (switching centre), the signals from each line are
> modulated onto a higher frequency for onward transmission down a trunk wire
> cable or fibre optic cable. The multiplexed high frequency modulated signals
> are down converted back to audio frequencies once they reach the intended
> destination.
>
> It is also possible to transmit this signal through the air (at incredibly
> low efficiencies and powers). The miles of cables snaking through the
> trenches in World War One were so long that messages could be intercepted by
> the enemy listening in without any direct connection to the system. A good
> ground connection and half a mile of wire rolled out across no mans land was
> sufficient to pick up the signals from the other side. Systems were also
> discovered which employed two widely separated ground connections and
> avoided the need to send men out on a suicide mission to carry wires towards
> the enemy trenches.
>
> Mike G0ULI- Hide quoted text -
>
> - Show quoted text -

.

On Jun 30, 12:46 pm, Radium <[email protected]> wrote:
> On Jun 30, 3:32 am, "Mike Kaliski" <[email protected]> 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?

.

On Jun 30, 12:55 pm, John Smith I <[email protected]> wrote:
> Radium wrote:
>
> > ...
>
> > 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:
>
> Use simple logic, you can modulate a dc (0 Hz) with higher freq (voice),
> (hint, your telephone line is an example) right?
>
> However, when you get into RF--possible, usable, desirable are seperate
> and distinct things.
>
> Again, with simple logic, modulating a 30 CPS signal with limited voice
> freq (say 5K wide) is going to create a LOT of harmonics and mixed
> signals, ain't it? Suggesting a very wide band receiver would be needed
> to begin with ... in my humble opinion, and for various reasons, NO, it
> is NOT possible ...
>
> Regards,
> JS

.