Peter

All of these depict an AM signal in the time dommain. This is not the
actual representation of the modulated signal. What you are seeing is
a complex addition of the three components of the AM signal versus
time. Anyone with an engineering degree from an accredited university
would know that. What your are seeing is not the frequency compents of
the AM signal itself. To see that properly requires a spectrum
analyzer. That will display the Fourier Transform of the many links
you have posted. In the frequency domain you will see that the carrier
remains canstant while the sideband amplitudes will varying as speech
varies. In the frequency domain you will see power versus frequency.
This is what your receiver sees, power versus frequency.

Oscilloscope representations are usefull in determining modulation
levels and not actually what is happening with the AM signal. To truel
see that requires a spectrum ananlyzer.

james

On Sun, 9 Sep 2007 05:30:47 +0100, " Peter"
wrote:

|"james" wrote...
| Peter
|
| I quote your message:
|
| "Amplitude Modulation... The output level "swings" above
| and below the carrier level."
|
| This is incorrect. The output does not swing above and
| below the carrier. The output of an AM signal is the
| carrier and the two sidebands.
|
|So? How are the sidebands excluded from "output level" in
|my statement which you quote, but change (twice missing out
|the word 'level') within your reply text?
|
|Is this your problem, you only see the words you want to?
|Then, considering output as being output frequency, rather
|than output level, you see an incorrect statement.
|
|Now, going back to my original statement, that output
|level (amplitude) "swings" (varies) above and below the
|carrier level (the amplitude of the unmodulated carrier)...
|
|http://upload.wikimedia.org/wikipedi...modulation.png
|http://robotics.eecs.berkeley.edu/~s...1_figure27.gif
|http://robotics.eecs.berkeley.edu/~s...1_figure37.gif
|http://www.st-andrews.ac.uk/~jcgl/Sc...part9/fig1.gif
|http://upload.wikimedia.org/wikipedi...ignals.svg.png
|
| Also power meters are not, per se, frequency specific.
|
|I made no mention of readings on a specific meter, just
|the actual output. Whatever you read on a meter does
|NOT change what the transmitter is actually putting out.
|
|Just like the last time, you appear to be either getting
|ahead of yourself or totally changing the topic.
|I am still unsure whether you are doing this on purpose,
|just for the sake of arguing, or have been snorting something.
|
| The problem is all RF is rectified to a time varying
| DC level
|
|What you do with a signal, once you receive it, makes
|no difference to what is actually being transmitted.
|
| that corresponds somewhat to the varying amplitudes
| of the RF signals being sampled.
|
|What varying amplitudes, you said it doesn't... and
|you can prove it by measuring the average.
|
|I really am having a hard time taking you seriously. Not
|only do you start ranting about things that have nothing
|to do with the issue (also commented on by someone else
|on the group), but you then go back on your whole
|argument.
|
|I really do have to consider the possibility that you are
|simply trying to wind people up and, like the Griffter,
|you will say anything that you believe will achieve your
|goal.
|
|
|Regards,
|Peter.
|