I'm
not sure what Jerry was hearing or
seeing. There are no reports of
any OTH facilities inside the US.
The OTH radar on HF ham
bands has been a problem in Europe
and beyond. It pops up here on the
east coast fairly often. You can
Google OTH and various ham radio
message boards and find a lot of
info. The radar operates by
choosing a frequency based on the
MUF and propagation at the radar
site. Sometimes this frequency will
be in the middle of a ham band. The
radar will change frequency
regularly. I've attached some
screen shots I took on different
bands. Note the times in UTC. This
interference is only a few kHz wide
as you can tune the radio up and
down the frequency and it will go
away. All of these were on standard
PSK31 frequencies. RX tuned to
10.040, 14.070, 21.070 and 7.070.
The 40 meter signal looks different
so I'm not sure what it is? Maybe
they change the PRF or it is from a
different source altogether.
I have worked thousands of EU
stations on PSK as I'm actively
pursuing EPC Awards and the EPC
gurus have triangulated and DF'd the
interference and say it is
definitely coming from Iran.
I know some other east coast 070
Members have mentioned this
interference from time to time.
Also, I'm in a very rural area.
Mostly farming and swamplands. No
cable TV, no DSL, I get WiFi from a
local provider that has his set up
on top of a farmer's grain bin and I
have no plasma TVs. I think there
are 3 residences within a 1/4 mile
of here. I do occasionally get some
electric fence pulsing on and off on
160 meters. I'm familiar with
powerline interference and it is
different.
Have fun. There are some 15
meter PSK31 signals here this
morning so it is good to see some
improvements in propagation.
Bill N4GBK in eastern North
Carolina
Milt,
I did the AM radio
trick several times in the
past and it works great.
Both were outside the QTH.
Once
I found an arcing fuse on a
pole and another time I
found a bad switching power
supply on a pole which was
used for lighting control.
One big clue was that it
only happened at night.
Once I told the town they
had their contractor come
out and replace it.
Ahhh....the
sweet sound of.....nothing!
Joe
KA1PPV #1482
Nope, as Bill, N4GBK,
said it's
probably OTH
(Over The
Horizon radar)
or similar on
20m. It only
happens for a
short time and
appears to be
some sort of
communications.
Definitely not
anything at my
QTH: if it
were in the
house it would
happen all the
time at
regular
intervals. It
almost has to
be here in US
because band
wasn't open to
Europe/Asia or
anywhere
overseas.
It's
just annoying
when it's on
but not as
annoying as
those really
wide 20m PSK
signals or
those using
RTTY, MFSK, or
have their
mics plugged
in when
sending on
PSK... this
morning I even
heard music
!
Geez, what ever
happened to
hams who cared
about their
signals ?
Jerry N9AVY
#454
From:
"'Milton Garb'
n6mg@... [070]"
<070@...>
To:
070@...
Sent:
Monday, July
18, 2016 11:11
AM
Subject:
RE: [070] Buzz
on 20m
Before
turning to the
masses for a
thousand
different
scenario’s,
&
opinions, have
you checked
your
collapsible
shack and
household for
a buzzing wall
wart, or even
the
little red/green
L.E.D. that
signifies
power to your
tv?
I get
it on 30m
rarely, but
unplugging my
wife’s flat
panel tv in
the kitchen
cures it.
I found
it by taking a
little $5
battery
powered AM
radio and
going from
room to room.
n6mg
Does any have any idea what that
raucous buzz
is that
sometimes
covers all the
PSK stations
up
??? It
shows as a
bunch of
vertical lines
all across the
waterfall.
Just
curious...
