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.

Radium wrote:
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.

I was not aware there was a compelling reason for analog cell phones to
stop using FM. Sounds like a solution looking for a problem.

Radium wrote:
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.

I really do think you need to revisit some VERY basic principles of
communications theory.

It sounds like you might have a causal peripheral understanding of
communications theory and stumbled upon some obscure radio propagation
concept and want to apply that obscure concept to to change the whole way
we think of communications. Ponder for a moment why said obscure concept
remained obscure.

I could go on and on and pick each of your comments apart...but it would be
a waste of time.

DTC hath wroth:

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.

"Extender". It was a 2nd almost identical receiver, tuned to a nearby
empty frequency. If there was any impulse (ignition) noise, both
receivers would detect the pulses. The 2nd (Extender) receiver would
block the IF signal in the main receiver for the duration of the
pulse. This resulted in a "hole" in the receive IF and audio, but it
was far less noticeable than if the pulse were allowed to be heard.
The tricky part of the design was getting the delays nearly identical
in the two receivers. It also made the 80D/140D/Motrac/Motran radios
rather huge and heavy. Extenders were considered a "standard option"
on most Low Band (30-50Mhz) radios as this is where the ignition noise
is the worst.

The more generic term "noise blanker" applies to this scheme, as well
as a mess of others that detect in a single receiver or blank in the
IF or audio. GE decided that "extender" was a good name for their
mobile repeater, and called it a "mobile extender" or more commonly
just "extender".
http://www.mbay.net/~wb6nvh/chpradio.htm
Egads. I'm cleaning house and found a large box of 40 year old
Motrash control heads and cables. Want some junk?

There was also a scheme to eliminate ignition noise that involved
running a wire to the points on the distributor. The assumption was
that there was a substantial delay between when the points opened, and
when the spark jumped in the spark plug. This allowed the receiver to
be blanked before the noise pulse arrived, which really improved the
noise blanker performance. I was working on the design when marketing
decided that it should tilt at other windmills. Only a few prototypes
were built, were never patented or produced, and worked really quite
well. Cheaper too. That was all just fine because cars were begining
to use electronic ignition systems, which didn't have easily
accessible ignition points.


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

In rec.radio.amateur.antenna DTC wrote:
Radium wrote:
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.

I really do think you need to revisit some VERY basic principles of
communications theory.

You're assuming he ever did anything more than assemble a list of
technical buzz words to string together at random.

Malaprop Man from the Frank and Ernest comic strip makes more sense.

--
Jim Pennino

Remove .spam.sux to reply.

DTC hath wroth:

It sounds like you might have a causal peripheral understanding of
communications theory and stumbled upon some obscure radio propagation
concept and want to apply that obscure concept to to change the whole way
we think of communications. Ponder for a moment why said obscure concept
remained obscure.

I could go on and on and pick each of your comments apart...but it would be
a waste of time.

Quite the contrary. Taking apart rants and speculation from the
lunatic fringe is great fun. After one has mastered science and
technology, it offers an additional challenge.

Haven't you ever listened to the old Art Bell show? He collected
callers claiming alien visitations, abductions, flying saucers,
conspiracies, ghosts, amazing technology, and all kinds of other
observed phenomenon best attributable to a general lack of sanity and
education. He would treat them quite seriously, drawing out
additional details that seem to fascinate his large and diverse
audience. My guess(tm) is that reality and accurate science are
fundamentally boring, and that speculation, lunacy and fantasy are
suitable diversions. Some of his callers held prestigious academic or
government positions, and apparently wanted to how far off the deep
end they could go. I recognized one or two. To properly present a
pseudoscientific hoax requires a good understanding of the science and
technology, and not just a word salad of buzzwords.

I must confess that I enjoy doing the same thing, as witnessed by this
ummm.... discussion. Lacking a suitable solution to the general lack
of technical sanity problem, I find it far more interesting to become
part of the problem. For example, my rants on being a werewolf:
http://www.LearnByDestroying.com/nooze/werewolf.txt

http://en.wikipedia.org/wiki/Art_Bell
In 1998, Bell was named as recipient of the less-than-prestigious
Snuffed Candle Award. The Council for Media Integrity cited Bell
"for encouraging credulity, presenting pseudoscience as genuine,
and contributing to the public's lack of understanding of the
methods of scientific inquiry."

That's why it's called "the magic of radio". When the magic wears
off, what's left is boring and mundane science and physics.

--
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:
Egads. I'm cleaning house and found a large box of 40 year old
Motrash control heads and cables. Want some junk?

Slacker...I tossed out all my old Moto stuff years ago. Last time I played
with the Motorola line was around the Micors came out. i used a few of them
for tower top UHF repeaters

Jeff Liebermann wrote:
[radically snipped]
Haven't you ever listened to the old Art Bell show?
Some of his callers held prestigious academic or
government positions, and apparently wanted to how far off the deep
end they could go.

I could be wrong as I'm going back to a late night show over five years ago
and I seem to recall it was one of his.

He was talking about GPS and played back a snippet of a conversation of
above mentioned prestigious academic person that went ballistic trying to
validate his credentials. But I digress...

I so wanted to point out that Art's (if indeed it was his show) was a
disingenuous presentation of GPS as it led the less informed to believe
there was a very dark and pervasive side to GPS. Continuing the only good
aspects of GPS were promoted by manufactures and dealers of GPS systems.

Good or bad...the bottom line was he attracted an audience and an audience
translates to advertising revenues.

wrote in message
...
You're assuming he ever did anything more than assemble a list of
technical buzz words to string together at random.

In this same spirit, I have decided how I would like to change the
electric toaster industry.

I believe that henceforth, all electric toasters should be made from
polished unobtainium with "Q"-shaped dilithium heating elements,
as it is obvious that this results in more even toasting of the bread
and an undeniably higher-fidelity output. Further, the toasted bread
should be ejected by carefully-aligned cavorite lifters, timed by
observing both the thermal state of the bread (detected through
counts of left-hand circular polarized neutrino emissions) and the
state of a resublimated thiotimoline crystal being exposed to the
transverse-modulated IR spectrum.

Discuss!

Bob "The New Radium" M.

"Jeff Liebermann" wrote in message
...
audience. My guess(tm) is that reality and accurate science are
fundamentally boring,

I think a lot of people perceive them as such, but that
perception is, without fail in my experience, the result of
a nearly-complete ignorance of these subjects on the parts
of those people. There are a practically infinite number
of incredibly interesting, beautiful, weird, mind-blowing things
going on in real science - if anything, it's the speculation,
lunacy, and fantasy that winds up looks really dull, if you
have any sort of understanding of the real world. Most of
what passes for interesting material on the Art Bell show
would be kicked out as too dull, too unimaginative, and/or too
mundane by any decent science-fiction editor.

Bob M.