Topband: Extreme directivity

[Tom Rauch]

> can be no denial of that.  The real issue is whether they 
> will add and
> subtract in a way so as to produce a 1.8MHz envelope and a 
> related wave
> front.

Ford,

The answer again is a definite NO, we cannot generate a new 
frequency unless there is a non-linear system that behaves 
as a mixer somewhere. When or if it does mix, it re-radiates 
with the conversion loss of that mixer and the efficiency of 
the antenna connected with or to that mixer.

There already was an experiment like this in Alaska called 
HAARP. See this link:

http://www.haarp.alaska.edu/

It takes thousands of megawatts ERP to affect the ionosphere 
enough to produce non-linearity, or even to affect it at 
all. The conversion efficiency would be horrible, just a 
tiny fraction of the power required put into an average 160 
antenna would produce a much stronger signal. The 
transmitters at HAARP are capable of over a GIGAWATT of RF, 
and they claim that is the magic threshold where the 
ionosphere is affected.

HAARP was originally intended to generate VLF signals by 
driving the ionosphere into non-linearity, but it appears 
they have abandoned that. Good luck on doing that on 160 
from the USA if they can't get it to work with gigawatts of 
ERP in the plasma of the auroral zone!

It's a good thing it works this way or the radio spectrum 
would be a real mess of intermod.

73 Tom