Topband: UW0MF re: Asian Jammer

[Tom Rauch]

> As described by the guys in JA, this is not pulse &
therefore
> cannot be OTHR.


 You are right Mr. BG.  It is not any sort of conventional
OHR RADAR. The recordings I've heard are either some sort of
information conveying  transmission or perhaps a
non-reflective type of object monitoring.

I can think of ways to watch signal phase distortion caused
by large moving objects on multiple receivers that would not
require a pulse, but there is nothing I have heard that
indicates this is a low frequency RADAR. It is very unlikely
this is a RADAR, because to sense an object the frequency of
the system has to be where the object looks large in terms
of wavelength. The object also has to be significantly more
or less conductive than the earth around it. Unless they are
looking for some target like ocean liners sailing in fresh
water lakes, I doubt it is RADAR.

Since this transmission is not pulsed with a short "on" time
duration like normal OTH RADAR, it cannot be blanked. The
easy cure is not an option for this noise.

It is possible to phase cancel it. If worse comes to worse
I'll design a system that will allow people to remove it
that way.

The sad part of this is over the years things are getting
worse for low bands. From reliable sources the noise floor
at HF has increased about 10dB is quiet locations. This is
from skywave propagated noise!!