[Chuck Forsberg]

On Mon, 28 May 2007 09:21:37 -0700, Radium wrote:

On May 27, 10:03 pm, "Mr.T" MrT@home wrote:

Bandwidth being more important for mobile phone conversations than
lower noise/interference in your opinion?

Bandwidth is more important for any/everything than lower noise/
interference in my opinion.

I like listening to long distance magnetic disruptions originating from
the objects in outer space significantly further than our solar system.

Which brings up another question.

Let's say I am in a space station which has a supercooled 150 KHz DX
analog receiver that receives the magnetic fields [while ignoring the
electric fields] of extremely weak 150 KHz AM analog carrier signals. In
addition, this receiver is so sensitive and powerful that it can clearly
pick up AM carrier waves as weak as 10^-10,000 watt [i.e. 10-
to-the-power-NEGATIVE-10,000 watt]. Also, this receiver has an
astronomically-powerful amplifier which amplifies the extremely-soft
carrier waves until the resulting modulation signals will be just loud
enough for the human ear to detect. Following this amplification, the
carrier waves are demodulation to modulation waves - the stuff we "hear"
- and then sent to loudspeaker so those onboard can hear those sounds.
In addition, the audio devices filter out modulation signals that are
below 20 Hz or above 20 KHz, as the human ear only responds to 20-20,000
Hz.

If I am on this spaceship, what will I hear on the radio? My guess is
that I would hear long-distance magnetic disruptions.

Most likely you would hear interference from nearby (in cosmic terms)
powerline systems. This noise will be attenuated by the
ionosphere but some will get through, and there's plenty of it
where it came from.

As to tropospheric bending ("skip"), this is a function of the weather
and frequency but not modulation. I received FM and TV stations
800+ miles away one summer morning in the 60s, and this is nowhere
near a record.

Not counting exotic modes, the most efficient voice modulation
is suppressed carrier single sideband, a form of AM.

--
/u/caf/signature.txt