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Old July 16th 07, 02:58 AM posted to sci.electronics.basics,rec.radio.shortwave,rec.radio.amateur.antenna,alt.cellular.cingular,alt.internet.wireless
Jeff Liebermann[_2_] Jeff Liebermann[_2_] is offline
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First recorded activity by RadioBanter: Jun 2007
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Default How I would like to change the cell phone industry [was AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency]

Radium hath wroth:

On Jul 15, 5:38 pm, Jeff Liebermann wrote:

Radium hath wroth:


AFAIK, the main issue with AM is that it is much more vulnerable to
magnetic disruptions than FM.


Wrong. Take a magnet, any magnet. Wave it around your AM or FM
radio. Hear anything different? You won't. Therefore, forget about
magnetic disturbances.


That's because this magnet isn't vibrating fast enough. If it were to
vibrate at the carrier frequency, you would most likely hear
something.


Actually, what you'll hear is whatever is driving the magnet at the
carrier frequency. For example, if you shove the magnet into a
solenoid coil, and drive the coil at 1MHz, the magnet will move very
slightly at 1MHz. However, the crud that you'll hear at 1MHz is
coming from the solenoid coil, not the magnet. If the magnetic field
cuts across some wire, that happens to be the antenna of your 1MHz
receiver, then yes, you'll hear something, but only if it's moving at
1MHz.

The AM audio cause by lightning is so boring.


If you've ever been hit by lightning, I don't think you'll find it
very boring. With 8 million hits per day, chances are good that
you'll get hit. Ummm... could you step outside for a moment?

All you get are clicks
and pops.


Oh no. It's much better than that. You get snap, crackle, pop,
crash, hiss, zap, buzz, braaaaaap, and other noises, all to the
accompanyment of loud thunder and the smell of ozone. It can also
make the fur stand up on your back. If all you hear are clicks and
pops, your receiver is comatose.

When the sun emits a prominence, that prominence causes high-power
waves of magnetic energy in the RF region to be emitted. These waves
can be heard on the AM radio on Earth. This is the sound that affects
CBs and other radio receivers using AM.


Ummm... coronal mass ejections and solar flares are particles, not
radio waves. The interference to radio communications is mostly from
these particles effects on the ionospheric layers. There is some RF
involved, but it's at microwave frequencies and requires a big radio
telescope to see.
http://www.nrao.edu/pr/2001/radiocme/

The main reason why anyone would prefer FM over AM is if they can't
handle these terrifying sounds w/out going hysterical.


Hmmm... All my communications radios except the aircraft navcom stuff
is FM. Maybe that explains why I'm spending time explaining to you
the basics. I'll try not to get too hysterical.

There are some who have had emotionally-strong experiences with these
sounds (...)


Not a problem. Everyone knows that too much RF rots the brain and
causes cancer of the vocabulary. Anyone involved in RF has to be
insane or will shortly be insane.

(chop...)

We tend to enjoy what we fear. At times.


I don't fear anything, so that might explain why I'm not enjoying
myself.

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