On Apr 11, 9:32*am, Cecil Moore wrote:
Keith Dysart wrote:
If care is taken with the selection of modulation
frequencies with regards to the carrier, then nodes
can be created on the transmission line and neither
the carrier nor the modulation will cross such a
node.

Please prove your assertion on the bench. Until you
do, there is little left to discuss.

Speculating that this is your way of asking for an
explantion...
With a shorted line, nodes occur every 90 degrees. These
90 degree nodal points are at different places on
the line for different frequencies because the
wavelengths are different. With the nodes at
different physical locations for the different
frequencies, when you sum the responses for all of
the frequencies there are no longer well defined
nodes.

If the frequencies are rational numbers, then
nodes for the total response will exist at the lowest
common multiples of the wavelengths, but it will
typically take a very long line to find one.

...Keith