"Brian Howie" wrote
...
In message , Dave
writes

"Szczepan Bialek" wrote in message
...
It seems that at long distances should appear the phenomenon of
frequency doubling.
See: http://www.rp-photonics.com/frequency_doubling.html

Is such?
S*
not that has been reported anywhere i have seen. this is likely because
that at the low amplitudes of radio waves relative to the energies needed
to create non-linear effects the medium is close enough to linear that any
doubling effect is too small to see.


You can get ionospheric mixing of radio waves. e.g Luxembourg Effect; so
doubling is possible.

You are right.


I have found this:
http://books.google.pl/books?id=QSke...P RA1-PA53,M1

There on the page 53 you can find that the medium-wave were disturbed by the
long-vave (halve-way between).
S*