[RFI] Continuous job keeping radio frequencies clean

[Don Kirk]

Two new cases of RFI this week.

*Case #1*
Within the last year I tracked down and eliminated 160 meters RFI that was
being generated by an injection molding machine located about 0.5 miles
from my house (generated by the AC servo drive controller).  This week I
noticed an identical interference pattern on 160 meters coming from the
same direction as before (using my 3 fixed pennants that provide amazingly
accurate signal direction).  Then I confirmed the interference was coming
from the injection molding facility using my portable DF gear.

I called the injection molding facility yesterday, and after a little
prodding, I was told a new injection molding machine was installed two
weeks ago (I was pretty sure this was the case as I knew they were going to
purchase 3 new machines this year based on my previous contact I had with
this facility).  I'm sure they will have to install a 3 phase in inline
power filter on this new machine similar to what we did on the first
machine, and will soon follow up with the owner of this facility.

*Case #2*
This week I also noticed a new interference pattern on 160 meters coming
from the S.E. (heading of 140 deg) and using my portable direction finding
equipment I tracked it down to my neighbors house and the suspect source
inside their house is located about 140 feet from my RX antennas.  I was
able to isolate the problem to the equipment inside their house associated
with their TV/internet service and/or wireless router (all located within
feet of each other), and our next step is to start unplugging these devices
until we find the guilty party (ran out of time last night to do this, and
will tackle this when we both have free time).  Turns out that some of this
equipment was relocated within the last two weeks which probably explains
why I just recently noticed it.

P.S. it really is nice having 3 identical point fed pennants on 160 meters
each pointing approximately 120 deg different than the other, as it
provides almost instantaneous signal direction (just takes one signal
strength reading on each antenna to determine the heading, and this can be
done within a couple of seconds).

Just FYI,

Don (wd8dsb)