On Jun 30, 2:55 pm, John Smith I 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

radium, I applaud you in your interest generating discussion.

if there are no questions there are no answers; dumb or smart!

to me your questions came across wonderfully, and generated both
responses.

as humans we stand on two legs, most of us that is.

men get the honor and privilage to stand on three legs from time to
time.

this is our blessing and our curse!

ps. how would u like to change the cell phone industry? and your
discussion group of course!

remeber all things are possible!!!!!!!!!!!!!!!!

On Jul 1, 7:24 am, wrote:
radium, I applaud you in your interest generating discussion.

if there are no questions there are no answers; dumb or smart!

to me your questions came across wonderfully, and generated both
responses.

as humans we stand on two legs, most of us that is.

men get the honor and privilage to stand on three legs from time to
time.

this is our blessing and our curse!


Thanks for your understanding.

ps. how would u like to change the cell phone industry?

Analog cells phones should stop using FM and should start using AM
between frequencies of 40,000 to 285,000 Hz.

As I learned recently, 40 KHz is the minimum radio frequency required
to coherently transmit/receive audio signals. The highest sound a
human can hear is 20 KHz. The radio-frequency used must be at least 2x
the intended frequency of the information being transmitted/received.

I chose 285 KHz to be the highest radio frequency for cell-phones
because it is roughly the highest-frequency categorized as "long wave"
radio.

and your
discussion group of course!

You mean the anti-yahoo group?

http://groups.google.com/group/yahoo...s?lnk=li&hl=en

"Radium" wrote in message
oups.com...
On Jul 1, 7:24 am, wrote:
Analog cells phones should stop using FM and should start using AM
between frequencies of 40,000 to 285,000 Hz.

I chose 285 KHz to be the highest radio frequency for cell-phones
because it is roughly the highest-frequency categorized as "long wave"
radio.


IDIOT!......complete idiot......

On Jul 1, 12:50 pm, "Porgy Tirebiter" wrote:
"Radium" wrote in message

oups.com...

On Jul 1, 7:24 am, wrote:
Analog cells phones should stop using FM and should start using AM
between frequencies of 40,000 to 285,000 Hz.

I chose 285 KHz to be the highest radio frequency for cell-phones
because it is roughly the highest-frequency categorized as "long wave"
radio.

- IDIOT!......complete idiot......

PT - Once again why waste your time replying
to his posts ? ? ? {Oops Like I Am Doing Too !}

Actually "Radium" would appear to be an
In-Complete-Want-To-Be driven by the 'urge'
to Post these Forever Ponding Questions
for others to charge at like Don Quijote's
quest to slay Windmills {a fool's errand}
http://en.wikipedia.org/wiki/Don_Quixote
http://en.wikipedia.org/wiki/Fool%27s_errand

FWIW - While many of his Post might fit into
the "sci.electronics.basics" NewsGroup; often
they would be consider OFF-TOPIC in other
NewsGroups like : rec.radio.shortwave,
rec.radio.amateur.antenna, alt.cellular.cingular,
alt.internet.wireless, etc

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

On 7/1/07 2:11 PM, in article
, "RHF"
wrote:

On Jul 1, 12:50 pm, "Porgy Tirebiter" wrote:
"Radium" wrote in message

oups.com...

On Jul 1, 7:24 am, wrote:
Analog cells phones should stop using FM and should start using AM
between frequencies of 40,000 to 285,000 Hz.

I chose 285 KHz to be the highest radio frequency for cell-phones
because it is roughly the highest-frequency categorized as "long wave"
radio.

- IDIOT!......complete idiot......

PT - Once again why waste your time replying
to his posts ? ? ? {Oops Like I Am Doing Too !}

Actually "Radium" would appear to be an
In-Complete-Want-To-Be driven by the 'urge'
to Post these Forever Ponding Questions
for others to charge at like Don Quijote's
quest to slay Windmills {a fool's errand}
http://en.wikipedia.org/wiki/Don_Quixote
http://en.wikipedia.org/wiki/Fool%27s_errand

FWIW - While many of his Post might fit into
the "sci.electronics.basics" NewsGroup; often
they would be consider OFF-TOPIC in other
NewsGroups like : rec.radio.shortwave,
rec.radio.amateur.antenna, alt.cellular.cingular,
alt.internet.wireless, etc

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 a teacher MUST be rational. You rate Radium with more potential than I
can. This most recent post is really off the wall.



-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
.
.
. .

On Jul 1, 2:28 pm, Don Bowey wrote:
On 7/1/07 2:11 PM, in article
om, "RHF"





wrote:
On Jul 1, 12:50 pm, "Porgy Tirebiter" wrote:
"Radium" wrote in message

groups.com...

On Jul 1, 7:24 am, wrote:
Analog cells phones should stop using FM and should start using AM
between frequencies of 40,000 to 285,000 Hz.

I chose 285 KHz to be the highest radio frequency for cell-phones
because it is roughly the highest-frequency categorized as "long wave"
radio.

- IDIOT!......complete idiot......

PT - Once again why waste your time replying
to his posts ? ? ? {Oops Like I Am Doing Too !}

Actually "Radium" would appear to be an
In-Complete-Want-To-Be driven by the 'urge'
to Post these Forever Ponding Questions
for others to charge at like Don Quijote's
quest to slay Windmills {a fool's errand}
http://en.wikipedia.org/wiki/Don_Quixote
http://en.wikipedia.org/wiki/Fool%27s_errand

FWIW - While many of his Post might fit into
the "sci.electronics.basics" NewsGroup; often
they would be consider OFF-TOPIC in other
NewsGroups like : rec.radio.shortwave,
rec.radio.amateur.antenna, alt.cellular.cingular,
alt.internet.wireless, etc

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 a teacher MUST be rational.
- You rate Radium with more potential than I can.
- This most recent post is really off the wall.

"Radium" -and- 'Rational' now there is an Oxymoron !
http://en.wikipedia.org/wiki/Oxymoron






-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
.
.
. .- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

DB remember that I did write :
Actually "Radium" would appear to be an
In-Complete-Want-To-Be driven by the 'urge'
to Post these Forever Ponding Questions
for others to charge at like Don Quijote's
quest to slay Windmills {a fool's errand}
http://en.wikipedia.org/wiki/Don_Quixote
http://en.wikipedia.org/wiki/Fool%27s_errand

On Sun, 01 Jul 2007 12:16:35 -0700, Radium
wrote:

On Jul 1, 7:24 am, wrote:
radium, I applaud you in your interest generating discussion.

if there are no questions there are no answers; dumb or smart!

to me your questions came across wonderfully, and generated both
responses.

as humans we stand on two legs, most of us that is.

men get the honor and privilage to stand on three legs from time to
time.

this is our blessing and our curse!


Thanks for your understanding.

ps. how would u like to change the cell phone industry?

Analog cells phones should stop using FM and should start using AM
between frequencies of 40,000 to 285,000 Hz.

---
Good idea. The available spectrum between 40kHz and 285kHz is
245kHz wide, so at a little less than 3kHz per channel the maximum
number of channels available would be 82. That means that no more
than 82 people can be on the air at the same time.

Probably all over the world, to boot, what with those frequencies
being able to propagate over long distances.

That's probably a good thing, because with those 1875 meter long 1/4
wave whips at 40kHz and those 263 meter 1/4 wave whips at 285kHz on
the mobiles, any more people on the air than that would certainly
create a hazardous situation.


--
JF

On 7/1/07 12:16 PM, in article
, "Radium"
wrote:

On Jul 1, 7:24 am, wrote:
radium, I applaud you in your interest generating discussion.

if there are no questions there are no answers; dumb or smart!

to me your questions came across wonderfully, and generated both
responses.

as humans we stand on two legs, most of us that is.

men get the honor and privilage to stand on three legs from time to
time.

this is our blessing and our curse!


Thanks for your understanding.

ps. how would u like to change the cell phone industry?

Analog cells phones should stop using FM and should start using AM
between frequencies of 40,000 to 285,000 Hz.

As I learned recently, 40 KHz is the minimum radio frequency required
to coherently transmit/receive audio signals. The highest sound a
human can hear is 20 KHz. The radio-frequency used must be at least 2x
the intended frequency of the information being transmitted/received.

I chose 285 KHz to be the highest radio frequency for cell-phones
because it is roughly the highest-frequency categorized as "long wave"
radio.

and your
discussion group of course!

You mean the anti-yahoo group?

http://groups.google.com/group/yahoo...s?lnk=li&hl=en


Darn it Radium, you just hit a new low.

See that teeney antenna on cell phones? Just how well do you think it will
radiate 285 kHz?

Radium hath wroth:

ps. how would u like to change the cell phone industry?

Analog cells phones should stop using FM and should start using AM
between frequencies of 40,000 to 285,000 Hz.

Analog cell phones are going to be history in the US on Feb 18, 2008.
Japan killed off analog around June 1999, Korea in Jan 2000, most of
Europe in 1997, etc.

40KHz thru 285Khz? Great idea. Just one minor problem. A 1/4 wave
antenna at about 100Khz frequency is 750 meters long. That's going to
be a rather large antenna for literally dragging behind you. Maybe a
balloon? Maybe a loop like this one?
http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=10850
Of course propagation might be a problem, as it will only work at
night and you'll have to connect to a cell site on the opposite coast
for those frequencies to work. The customers can be ignored when they
complain about atmospheric static and noise.

Of course, 240KHz of usable bandwidth is much less than the hundreds
of MHz currently in use by cellular providers, so there will
substantially fewer users. Let's see.... there are 240 million
subscribers in the US. Your AM system can handle about 40 users (6KHz
channels), so your cell phone bill will only be 6 million times larger
than it is currently. Now do you see why the microwave bands are so
in demand for cellular.

As I learned recently, 40 KHz is the minimum radio frequency required
to coherently transmit/receive audio signals.

Coherently? I would be worried if you planned to incoherently
transmit/receive audio signals. Perhaps if you added 40KHz to your
word salad, it would make your blather more coherent. (Hint: Look
up the definition of coherent and then use it where appropriate).

Actually, you're close. 40KHz is the common frequency used by
ultrasonic TV remote controls. I've seen PWM modulation system using
a pair of these to act as a crude cordless phone (that doesn't require
FCC type certification). You could probably go down to 20KHz, but
then intermodulation products (mixes) between the audio and the
carrier will begin to be a problem. Congratulations, you got one
thing mostly correct.

The highest sound a
human can hear is 20 KHz.

Voice is from 300 to 3000Hz. You could probably get away with 300 to
2400Hz. If you're planning to transmitting AM hi-fi or data, then you
might need the 20KHz.

The radio-frequency used must be at least 2x
the intended frequency of the information being transmitted/received.

Ummm... no. You're apparently thinking of the Shannon rule for
information bandwidth:
http://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem
If your input audio is perhaps bandwidth limited to 3KHz, a 6KHz
carrier will not work. You'll get considerable mixing (aliasing) and
audio intermodulation crud. The carrier would need to be somewhat
higher in frequency as limited by whatever output RF filtering is
used.

I chose 285 KHz to be the highest radio frequency for cell-phones
because it is roughly the highest-frequency categorized as "long wave"
radio.

Nope. See details at:
http://en.wikipedia.org/wiki/Longwave


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

Jeff Liebermann wrote:

40KHz thru 285Khz? Great idea. Just one minor problem. A 1/4 wave
antenna at about 100Khz frequency is 750 meters long. That's going to
be a rather large antenna for literally dragging behind you.

Well, your math is correct. However, the so-called "atomic" wrist
watches receive their time signal from WWVB which transmits at 60kHz.

How do they get that 1250 meter long antenna ( 1/4 wave at 60 kHz)
inside that itty bitty wrist watch case? ;-)