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  1. #1
    Jeff Liebermann
    Guest
    Radium <[email protected]> hath wroth:

    >> how would u like to change the cell phone industry?

    >
    >Analog cells phones should stop using FM and should start using AM
    >with SHF frequencies - at least 3 GHz and at most 30 GHz.
    >
    >http://en.wikipedia.org/wiki/Super_high_frequency


    Maybe if the entire cellular infrastructure would move up to the LMDS
    26-30GHz band, I might recover some of the money I sunk into an LMDS
    startup. Great idea. I like it.

    Of course, there are problems. Nobody makes an economical mm wave
    handset. There will probably need to be 8-10 times more cell sites
    built than are currently in use on 800/900 and 1800/1900MHz. Of
    course mm wave propagation is affected by just about everything, so it
    probably won't work indoors. No problem, just add more cell sites and
    repeaters. Of course you couldn't get away with the existing
    relatively low power output handsets and insipid gain antennas, so
    we'll just crank up the power and antenna gain on the handset and fry
    a few peoples brains. It's a small sacrifice to make so I watch TV on
    my cell phone.

    >Equally important, SHF frequencies can efficiently transmit signals
    >using extremely small transmitters. Longer wavelengths require larger
    >transmitters.


    They do? I didn't know that. My 49MHz automobile alarm dongle isn't
    much larger than my 2400MHz USB wi-fi dongle. Are you sure the
    transmitter has to be bigger or were you thinking of the antenna?

    >Obviously there are frequencies lower than SHF -- VHF and above --
    >that can easily penetrate charged particles [e.g. anything resembling
    >the ionosphere or heliosphere].


    I don't know of any wireless service provider that charges for
    particles. What are they charging and what's the stock symbol? I've
    always suspected that charged particles might be worth selling.

    >However, lower-frequencies tend to
    >result in less bandwidth, so it is better to use higher-frequencies
    >when the application requires significant bandwidth.


    Hint: It doesn't matter what you're doing, there's never enough
    bandwidth available. If you provide XX MHz of available bandwidth,
    someone will immediately supply an application that required 10 times
    the available bandwidth. More simply, applications tend to fill up
    available bandwidth quite rapidly.

    >I choose AM because it requires less bandwidth than FM. In addition,
    >AM tends to retain reception of rather weak signals, while FM
    >"considers" such signals to be absent.


    I'll make it really simple for you. FM is "hi-fi", while AM is noisy
    "no-fi". Don't you want to be cool strutting down the street with
    your iPhone watching HDTV with 7.1 sound? It wouldn't do to have it
    sound like the typical AM broadcast station. For decent quality, you
    gotta have FM.

    This is fun. Kinda reminds me of some of the business plans I
    reviewed during the dot com boom.

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



    See More: How I would like to change the cell phone industry [was AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency]




  2. #2
    RHF
    Guest

    . . . How I would like to change the cell phone industry [was Re: AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency]

    On Jul 15, 2:14 pm, Jeff Liebermann <[email protected]> wrote:
    > Radium <[email protected]> hath wroth:
    >
    > >> how would u like to change the cell phone industry?

    >
    > >Analog cells phones should stop using FM and should start using AM
    > >with SHF frequencies - at least 3 GHz and at most 30 GHz.

    >
    > >http://en.wikipedia.org/wiki/Super_high_frequency

    >
    > Maybe if the entire cellular infrastructure would move up to the LMDS
    > 26-30GHz band, I might recover some of the money I sunk into an LMDS
    > startup. Great idea. I like it.
    >
    > Of course, there are problems. Nobody makes an economical mm wave
    > handset. There will probably need to be 8-10 times more cell sites
    > built than are currently in use on 800/900 and 1800/1900MHz. Of
    > course mm wave propagation is affected by just about everything, so it
    > probably won't work indoors. No problem, just add more cell sites and
    > repeaters. Of course you couldn't get away with the existing
    > relatively low power output handsets and insipid gain antennas, so
    > we'll just crank up the power and antenna gain on the handset and fry
    > a few peoples brains. It's a small sacrifice to make so I watch TV on
    > my cell phone.
    >
    > >Equally important, SHF frequencies can efficiently transmit signals
    > >using extremely small transmitters. Longer wavelengths require larger
    > >transmitters.

    >
    > They do? I didn't know that. My 49MHz automobile alarm dongle isn't
    > much larger than my 2400MHz USB wi-fi dongle. Are you sure the
    > transmitter has to be bigger or were you thinking of the antenna?
    >
    > >Obviously there are frequencies lower than SHF -- VHF and above --
    > >that can easily penetrate charged particles [e.g. anything resembling
    > >the ionosphere or heliosphere].

    >
    > I don't know of any wireless service provider that charges for
    > particles. What are they charging and what's the stock symbol? I've
    > always suspected that charged particles might be worth selling.
    >
    > >However, lower-frequencies tend to
    > >result in less bandwidth, so it is better to use higher-frequencies
    > >when the application requires significant bandwidth.

    >
    > Hint: It doesn't matter what you're doing, there's never enough
    > bandwidth available. If you provide XX MHz of available bandwidth,
    > someone will immediately supply an application that required 10 times
    > the available bandwidth. More simply, applications tend to fill up
    > available bandwidth quite rapidly.
    >
    > >I choose AM because it requires less bandwidth than FM. In addition,
    > >AM tends to retain reception of rather weak signals, while FM
    > >"considers" such signals to be absent.

    >
    > I'll make it really simple for you. FM is "hi-fi", while AM is noisy
    > "no-fi". Don't you want to be cool strutting down the street with
    > your iPhone watching HDTV with 7.1 sound? It wouldn't do to have it
    > sound like the typical AM broadcast station. For decent quality, you
    > gotta have FM.
    >
    > This is fun. Kinda reminds me of some of the business plans I
    > reviewed during the dot com boom.
    >
    > --
    > Jeff Liebermann [email protected]
    > 150 Felker St #D http://www.LearnByDestroying.com
    > Santa Cruz CA 95060http://802.11junk.com
    > Skype: JeffLiebermann AE6KS 831-336-2558


    .. . .




  3. #3
    Radium
    Guest

    Re: How I would like to change the cell phone industry [was Re: AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency]

    On Jul 15, 2:14 pm, Jeff Liebermann <[email protected]> wrote:

    > Radium <[email protected]> hath wroth:


    > >> how would u like to change the cell phone industry?


    > >Analog cells phones should stop using FM and should start using AM
    > >with SHF frequencies - at least 3 GHz and at most 30 GHz.


    > >http://en.wikipedia.org/wiki/Super_high_frequency


    > There will probably need to be 8-10 times more cell sites
    > built than are currently in use on 800/900 and 1800/1900MHz.


    Why?

    > >Equally important, SHF frequencies can efficiently transmit signals
    > >using extremely small transmitters. Longer wavelengths require larger
    > >transmitters.


    > They do? I didn't know that. My 49MHz automobile alarm dongle isn't
    > much larger than my 2400MHz USB wi-fi dongle. Are you sure the
    > transmitter has to be bigger or were you thinking of the antenna?


    Maybe the antenna.

    > >I choose AM because it requires less bandwidth than FM. In addition,
    > >AM tends to retain reception of rather weak signals, while FM
    > >"considers" such signals to be absent.


    > I'll make it really simple for you. FM is "hi-fi", while AM is noisy
    > "no-fi".


    FM has too much hiss. FM signals are lost very easily. AM tends to
    retain reception of a signals even when this signal is extremely weak.
    In FM, once you go below a certain wattage, you completely lose the
    signal, and the annoying hiss begins. With AM it is much easier to
    receive the low-power signal.

    AM maybe more vulnerable to electronic disturbances but so what? The
    magnetic RF interferences that are heard on the AM radio are
    entertaining compared to the deafening hiss on the FM radio.

    > For decent quality, you
    > gotta have FM.


    Nope. For decent quality sound you need audio that is uncompressed PCM
    [similar to CDs and WAVE files] with a sample rate of at least 44.1
    KHz and a bit-resolution of at least 16-bit. Or the analog equivalent.




  4. #4
    John Fields
    Guest

    Re: How I would like to change the cell phone industry [was Re: AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency]

    On Sun, 15 Jul 2007 14:45:06 -0700, Radium <[email protected]>
    wrote:

    >On Jul 15, 2:14 pm, Jeff Liebermann <[email protected]> wrote:
    >
    >> Radium <[email protected]> hath wroth:

    >
    >> >> how would u like to change the cell phone industry?

    >
    >> >Analog cells phones should stop using FM and should start using AM
    >> >with SHF frequencies - at least 3 GHz and at most 30 GHz.

    >
    >> >http://en.wikipedia.org/wiki/Super_high_frequency

    >
    >> There will probably need to be 8-10 times more cell sites
    >> built than are currently in use on 800/900 and 1800/1900MHz.

    >
    >Why?
    >
    >> >Equally important, SHF frequencies can efficiently transmit signals
    >> >using extremely small transmitters. Longer wavelengths require larger
    >> >transmitters.

    >
    >> They do? I didn't know that. My 49MHz automobile alarm dongle isn't
    >> much larger than my 2400MHz USB wi-fi dongle. Are you sure the
    >> transmitter has to be bigger or were you thinking of the antenna?

    >
    >Maybe the antenna.
    >
    >> >I choose AM because it requires less bandwidth than FM. In addition,
    >> >AM tends to retain reception of rather weak signals, while FM
    >> >"considers" such signals to be absent.

    >
    >> I'll make it really simple for you. FM is "hi-fi", while AM is noisy
    >> "no-fi".

    >
    >FM has too much hiss. FM signals are lost very easily. AM tends to
    >retain reception of a signals even when this signal is extremely weak.
    >In FM, once you go below a certain wattage, you completely lose the
    >signal, and the annoying hiss begins. With AM it is much easier to
    >receive the low-power signal.
    >
    >AM maybe more vulnerable to electronic disturbances but so what? The
    >magnetic RF interferences that are heard on the AM radio are
    >entertaining compared to the deafening hiss on the FM radio.
    >
    >> For decent quality, you
    >> gotta have FM.

    >
    >Nope. For decent quality sound you need audio that is uncompressed PCM
    >[similar to CDs and WAVE files] with a sample rate of at least 44.1
    >KHz and a bit-resolution of at least 16-bit. Or the analog equivalent.


    ---
    Wrong.


    --
    JF



  5. #5
    Jeff Liebermann
    Guest

    Re: How I would like to change the cell phone industry [was Re: AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency]

    Radium <[email protected]> hath wroth:

    >> There will probably need to be 8-10 times more cell sites
    >> built than are currently in use on 800/900 and 1800/1900MHz.


    >Why?


    For a given radio system, higher frequencies don't go as far as lower
    frequencies. You can see how it works by just plugging in different
    frequencies a "free space loss" calculator such as:
    <http://www.terabeam.com/support/calculations/free-space-loss.php>
    For every 6dB of additional path loss, your range is cut in half.
    Incidentally, this is not my idea or a conspiracy. Mother nature made
    it that way and we have to live with the physics.

    >> I'll make it really simple for you. FM is "hi-fi", while AM is noisy
    >> "no-fi".

    >
    >FM has too much hiss.


    FM has a limiter that eliminates all AM noise components. That's
    exactly the way the soon to be obsolete analog cell phones operate. If
    you're hearing hiss, then there's something broken in your FM stereo.

    >FM signals are lost very easily.


    I have a lost and found for missing signals. It's called a spectrum
    analyzer. If the signal wanders, I can usually find it. Not a
    problem.

    >AM tends to
    >retain reception of a signals even when this signal is extremely weak.


    Not really. If you really want weak signal reception, I suggest you
    look into SSB (scientific set back) modulation. Half the bandwidth
    gives you twice the sensitivity.

    >In FM, once you go below a certain wattage, you completely lose the
    >signal, and the annoying hiss begins. With AM it is much easier to
    >receive the low-power signal.


    Nope. All FM receivers have a squelch to mute the receiver when
    there's not enough signal to make it worth listening. The squelch is
    much more efficient with FM than an AGC operated squelch for AM.
    Anyway, if someone calls with me on my cell phone with a crummy
    signal, I don't want to talk to them and I usually ask them to call me
    back when in a better area.

    The problem with AM audio is that the ultimate signal to noise ratio
    isn't very good. AM is noisy at any signal strength. The noise never
    really goes away. On the other foot, FM is noisy with very weak
    signals, but becomes very quiet once the limiter starts to work.
    That's why FM is preferred for music and why analog AM broadcasting
    sounds marginal at any signal level.

    >AM maybe more vulnerable to electronic disturbances but so what? The
    >magnetic RF interferences that are heard on the AM radio are
    >entertaining compared to the deafening hiss on the FM radio.


    If your FM radio has a deafening hiss, you're probably not tuned to
    any station. Try listening to a station instead of between stations.
    If it has an AFC, turn it on. There may also be some kind of
    malfunction in your hi-fi as you should not be hearing any hiss when
    tuned to a station.

    >> For decent quality, you
    >> gotta have FM.


    >Nope. For decent quality sound you need audio that is uncompressed PCM
    >[similar to CDs and WAVE files] with a sample rate of at least 44.1
    >KHz and a bit-resolution of at least 16-bit. Or the analog equivalent.


    I thought you didn't like digital? You only gave me a choice of AM or
    FM. Now, you want digital. Well, digital is what today's cell phones
    use mostly to maximize spectrum efficiency. With compression and
    proper coding, you can pickup quite a bit of efficiency, at the
    expense of sounding like you're gargling ball bearings. Not too bad a
    tradeoff for voice. Really awful for music. Fortunately, none of the
    broadcasters or cellular carriers use raw CD data, mostly because it's
    not compressed.

    So, are you ready to go public with your idea? When's the IPO?

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



  6. #6
    Brenda Ann
    Guest

    Re: How I would like to change the cell phone industry [was Re: AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency]


    "Jeff Liebermann" <[email protected]> wrote in message
    news:[email protected]
    > I'll make it really simple for you. FM is "hi-fi", while AM is noisy
    > "no-fi". Don't you want to be cool strutting down the street with
    > your iPhone watching HDTV with 7.1 sound? It wouldn't do to have it
    > sound like the typical AM broadcast station. For decent quality, you
    > gotta have FM.


    FM is not inherently any more 'hi-fi' than AM. Fidelity is a product of
    bandwidth, not modulation type. AM is not even so susceptible to noise as
    the frequency goes up, since the energy of the noise pulses goes down
    logarithmically as frequency goes up. AM is used for aeronautical
    communications very successfully for several reasons, one of which is the
    LACK of 'capture effect'. There are still some frequencies where AM will be
    more susceptible to interference than FM, but FM would still suffer, for
    instance the segment between 1330-1400 MHz which is the natural frequency of
    Hydrogen (lots of that around).






  7. #7
    Jeff Liebermann
    Guest

    Re: How I would like to change the cell phone industry [was Re: AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency]

    "Brenda Ann" <[email protected]> hath wroth:

    >"Jeff Liebermann" <[email protected]> wrote in message
    >news:[email protected]
    >> I'll make it really simple for you. FM is "hi-fi", while AM is noisy
    >> "no-fi". Don't you want to be cool strutting down the street with
    >> your iPhone watching HDTV with 7.1 sound? It wouldn't do to have it
    >> sound like the typical AM broadcast station. For decent quality, you
    >> gotta have FM.


    >FM is not inherently any more 'hi-fi' than AM.


    FM was invented by Edwin Armstrong specifically to eliminate the noise
    problems of AM broadcasting. What I think you might be referring to
    is the huge pissing match between Armstrong and John Carson over
    whether FM was any better than FM in the 1930's. The consensus is
    that very narrow band FM isn't that much better than AM (of equal
    occupied bandwidth), but wide band FM (as used in broadcast FM and TV)
    is far better than AM for just about everything.
    <http://fecha.org/armstrong.htm>

    >Fidelity is a product of
    >bandwidth, not modulation type.


    Correct. Actually, it's also a function of modulation linearity
    (distortion and intermod) and encoding method (dynamic range), but I
    don't wanna slither down that diversion. Pretend I didn't mention it.

    >AM is not even so susceptible to noise as
    >the frequency goes up, since the energy of the noise pulses goes down
    >logarithmically as frequency goes up.


    If you're thinking of impulse noise, you're mostly correct. However,
    there are plenty of other sources of AM noise available. For example,
    the typical VHF aircraft radio requires substantial filtering of the
    magneto to avoid hash. Same with any onboard motor. If you've ever
    tried to install a TV (VSB is a form of AM) in a vehicle, you'll also
    find that ignition and motor noise can be a problem.

    Also, your statement isn't quite right. I think what you meant to say
    is that as the frequency increases, the energy produced by an impulse
    source, in a given bandwidth, goes down. Even that's not accurate as
    I have a fluorescent lamp calibrated noise source that's quite noisy
    well into the GHz range.

    >AM is used for aeronautical
    >communications very successfully for several reasons, one of which is the
    >LACK of 'capture effect'.


    The FAA, FCC, and various manufactories have tried to move aircraft
    radios away from AM and towards FM several times in the past 30 year
    or so. They failed mostly due to international WRC reluctance to swap
    out expensive radios. It took literally forever to get GPS receivers
    TSO approved and about 15 years for nav/com radios to go from 50KHz to
    25KHz channel spacing, and that was just the FAA. Where else can you
    find an industry, where progress is somewhat retarded by a regulatory
    agency of the federal government?

    I listen to a mix of VHF aircraft AM channels and FM ham and public
    safety channels on my scanner almost constantly. It's easy to
    recognize the AM stations by their uniformly crappy audio.

    Most domestic ground to ground airport traffic is now all FM, as is
    military ground to ground and ground to air. The reason is that it's
    difficult to find a decent AM aircraft band walkie talkie. So, they
    use commercial FM radios. The only AM walkie talkies are used by
    experimental aviation and ultralights, some of which do not have much
    of an electrical system that can handle the grossly inefficient AM
    transmitters.

    Also, nobody really cares about the "capture effect" as the tower
    usually has multiple receiver sites and can generally deal with
    simultaneous transmit collisions. However, they do care about the
    heterodynes produced by simultaneous transmissions, which obliterate
    both transmissions. With FM, they could use commercial receiver
    voting systems and largely eliminate the problem.

    >There are still some frequencies where AM will be
    >more susceptible to interference than FM, but FM would still suffer, for
    >instance the segment between 1330-1400 MHz which is the natural frequency of
    >Hydrogen (lots of that around).


    If my AM or FM receiver is sensitive enough to hear something in the
    "water hole", it would be attached to a very big dish antenna.


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



  8. #8

    Re: How I would like to change the cell phone industry [was Re: AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency]

    In rec.radio.amateur.antenna Jeff Liebermann <[email protected]> wrote:
    > Radium <[email protected]> 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. The main issue with AM is susceptibility to
    > pulsed noise, as found in motors, fans, auto engines, and computahs.
    > FM doesn't have as bad a problem because the limiter in the receiver
    > clips everything to the same level, thus reducing the effect.


    > >That is why when you are listening to
    > >the AM radio at home and someone turns on the microwave-oven, you here
    > >those odd sounds on the receiver.


    > No. Microwave ovens operate at 2400Mhz. AM broadcast operates at
    > 1MHz. No way there's going to be any interference there. However,
    > the microwave oven may have a fan or CPU that runs the display, that
    > belches garbage at 1MHz. I just tried mine and there's a tiny bit of
    > buzz coming from the display section when I shove an AM radio right up
    > to the display. If that's what you're hearing, I would test it with a
    > different microwave oven. If only yours has the problem, I suggest
    > you consider a replacement.


    > >Also, if there is a solar prominence you can hear the resulting
    > >magnetic disruptions on an AM radio receiver. They sound scary and
    > >enjoyable at the same time.


    > You can also hear lightning storms. In the US, most of those are in
    > the south east of the country. Nothing like interference from 3000
    > miles away. Lightning detectors operate in the 25-50KHz region.
    > Incidentally, there are about 8 million lightning hits per day, which
    > is why the noise sounds almost continuous.


    > (chomp...)


    > Sorry, my time is up. Please insert $0.25 for the next 3 minutes.


    Don't tell him about whistlers.

    --
    Jim Pennino

    Remove .spam.sux to reply.



  9. #9
    Radium
    Guest

    Re: How I would like to change the cell phone industry [was Re: AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency]

    On Jul 15, 5:38 pm, Jeff Liebermann <[email protected]> wrote:

    > Radium <[email protected]> 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.

    > >Also, if there is a solar prominence you can hear the resulting
    > >magnetic disruptions on an AM radio receiver. They sound scary and
    > >enjoyable at the same time.


    > You can also hear lightning storms. In the US, most of those are in
    > the south east of the country. Nothing like interference from 3000
    > miles away. Lightning detectors operate in the 25-50KHz region.
    > Incidentally, there are about 8 million lightning hits per day, which
    > is why the noise sounds almost continuous.


    The AM audio cause by lightning is so boring. All you get are clicks
    and pops. Now a solar prominence, this results in some terrifying
    tones on the AM radio, they resemble the second set of tones played by
    the Emergency Alert System -- the higher-pitched tones. At times the
    cosmically-induced AM radio disruptions sound like the audio you get
    when playing the 1st level of the 1st-stage of Super Mario Bros 1 on
    channel 4, when the receiver is connected to channel 3. Instead of
    hearing the game's music, you here those frightening yet enjoyable
    tones. Sometime you can here these same sounds on a PA system or an
    airplane. When I was in 1st-grade, the schoolbus I went in had a CB
    radio which would often make these scary sounds. Such sounds would --
    and still to a much smaller extent -- make my eyes water in fear,
    dissociation, enjoyment, and psychdelia.

    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.

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

    There are some who have had emotionally-strong experiences with these
    sounds -- perhaps a fire on an aircraft -- when these sounds are
    heard, flashbacks occur which can entirely consume an individual's
    psyche. Such an individual might not even know why he/she is getting
    psychologically-excited while listening to the sounds because the
    brain involuntarily suppresses emotionally-intense memories.

    Here is what use to happen -- and still happens to some extent -- to
    me when I hear the sounds I describe:

    1. Psychogenic shock and psychological dissociation due to the extreme
    fear/enjoyment caused by the sounds.
    2. Flashbacks of my house in Stamford, Connecticut in which my parents
    and me moved out when I was around 2.5 years of age.
    3. Enjoyable yet terrifying thoughts about outer space due to the
    knowledge/belief that the source of the sounds is in outer space
    4. Fear of -- and obsession with -- magnetism due to knowledge/belief
    that the radio waves are magnetic
    5. Decrease in heart rate
    6. Slow deep breathing
    7. Muscle relaxation
    8. Increased tear production

    Ain't it interesting when things that are so scary are also so
    enjoyable at the same time. Why else would they develop virtual
    reality systems? Or visit outer space?

    We tend to enjoy what we fear. At times.




  10. #10
    Jeff Liebermann
    Guest

    Re: How I would like to change the cell phone industry [was Re: AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency]

    Radium <[email protected]> hath wroth:

    >On Jul 15, 5:38 pm, Jeff Liebermann <[email protected]> wrote:
    >
    >> Radium <[email protected]> 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 [email protected]
    150 Felker St #D http://www.LearnByDestroying.com
    Santa Cruz CA 95060 http://802.11junk.com
    Skype: JeffLiebermann AE6KS 831-336-2558



  11. #11
    John Larkin
    Guest

    Re: How I would like to change the cell phone industry [was Re: AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency]

    On Sun, 15 Jul 2007 16:30:13 -0700, Jeff Liebermann <[email protected]>
    wrote:


    >Not really. If you really want weak signal reception, I suggest you
    >look into SSB (scientific set back) modulation.


    what??!! ^^^^^^^^^^^^^^^^^^^


    John





  12. #12

    Re: How I would like to change the cell phone industry [was Re: AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency]

    In rec.radio.amateur.antenna John Larkin <[email protected]> wrote:
    > On Sun, 15 Jul 2007 16:30:13 -0700, Jeff Liebermann <[email protected]>
    > wrote:



    > >Not really. If you really want weak signal reception, I suggest you
    > >look into SSB (scientific set back) modulation.


    > what??!! ^^^^^^^^^^^^^^^^^^^


    Too subtle for you?

    It's called humor.

    --
    Jim Pennino

    Remove .spam.sux to reply.



  13. #13
    Jeff Liebermann
    Guest

    Re: How I would like to change the cell phone industry [was Re: AM electromagnetic waves: 20 KHz modulation frequency on an astronomically-low carrier frequency]

    John Larkin <[email protected]> hath wroth:

    >On Sun, 15 Jul 2007 16:30:13 -0700, Jeff Liebermann <[email protected]>
    >wrote:
    >>Not really. If you really want weak signal reception, I suggest you
    >>look into SSB (scientific set back) modulation.


    >what??!! ^^^^^^^^^^^^^^^^^^^


    Sigh. Nobody here seems to have a sense of humor.
    SSB = Single Side Band
    Happy now? You sure take the fun out of acronym mutilation.

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



  14. #14
    DTC
    Guest

    Re: How I would like to change the cell phone industry [was Re: AM

    Jeff Liebermann wrote:
    > 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?


    Reminds me of an afternoon when I was 600 ft up a 1,000 ft TV tower
    climbing on the inside. The tower took a hit and the lightning bolt
    followed a aircraft cable hoist line down the inside of the tower. Right
    between my legs.



  15. #15
    DTC
    Guest

    Re: How I would like to change the cell phone industry [was Re: AM

    Jeff Liebermann wrote:
    > If you're thinking of impulse noise, you're mostly correct. However,
    > there are plenty of other sources of AM noise available. For example,
    > the typical VHF aircraft radio requires substantial filtering of the
    > magneto to avoid hash. Same with any onboard motor. If you've ever
    > tried to install a TV (VSB is a form of AM) in a vehicle, you'll also
    > find that ignition and motor noise can be a problem.


    Dang it...my memory is slipping. What did Motorola call their noise
    filtering circuit on their old low band Motracs. Extenders[tm]? As I recall
    it was a simple noise blanker.



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