On Sun, 16 Sep 2007 18:47:06 +0100, " Peter"
wrote:

|"james" wrote...
| Peter
|
| All of these depict an AM signal in the time dommain.
|
|Exactly, amplitude variations over time... modulation (AM).
|
|This is like pulling teeth.
|
| Oscilloscope representations are usefull in determining
| modulation levels
|
|Exactly... modulation (AM) levels.
|
|Several teeth, without anaesthetic.
|
| and not actually what is happening with the AM signal. To
| truel see that requires a spectrum ananlyzer.
|
|Wrong.
|
|The instrument of choice depends upon exactly what it
|is you want to know about the signal. The spectrum analyzer
|does not tell you everything you may wish to know. Otherwise,
|all other instuments would now be obsolete.
|
|As you stated above, the oscilloscope IS useful for
|determining modulation... which is what this was all about.
|That was, until you decided to whine on about what the
|sidebands are doing.
|
|The spectrum analyzer will show you the sidebands, but if
|you want to see the modulation (AM) then the oscilloscope
|is the tool for the job.
|
|Different tools for different purposes.
|
|Come on James, this has to be a game you are playing. I really
|don't have time for such games - do you?
|
|
|Regards,
|Peter.
|
|-----------

AM is a complex signal made up of many sinusoidal waveforms that can
only be seen in their individual components with a spectrum analyzer.
IF you know how to use one it will yield far more information about
your AM signal than an osscilloscope could ever yield. IF you know how
to use a spectrum analyzer, you can determine percentage of
modulation, ie modulation index, as well as the power of all three
components. Not hardly capable with an oscilloscope. The oscillocope
is best for those less technically inclined to depict what is
happening with an AM signal.

You have no time for games? Then why bother with this group?

james