Can anyone identify these interfering signals on 10 Meters?

  • 1
  • Question
  • Updated 4 years ago
I observed these alternating signals on 10 Meters this morning (10/3/2014) at about 1300Z
#2 sounded for about 5 seconds and was answered by # 1 for about three seconds.
This back-and-forth repeated for at least 15 minutes while I was getting screen shots of it.
It stopped for about 10 seconds and I thought it was done, but started up again.
It is about 75 Khz wide.

It looks like some kind of wide band digital file transfer.
It experienced fading consistent with morning HF propagation so I don't think it is local.

Any takers?

Ken - NM9P
Photo of Ken - NM9P

Ken - NM9P, Elmer

  • 3875 Posts
  • 1179 Reply Likes
  • curious and frustrated.

Posted 4 years ago

  • 1
Photo of Jim, KJ3P

Jim, KJ3P

  • 88 Posts
  • 12 Reply Likes
Frequencies?
Photo of Duane, AC5AA

Duane, AC5AA

  • 383 Posts
  • 84 Reply Likes
Sound files would help too!
Photo of Reg

Reg

  • 120 Posts
  • 73 Reply Likes

Ken:

Can you post the screen shots?

Reg

Photo of Ken - NM9P

Ken - NM9P, Elmer

  • 3875 Posts
  • 1179 Reply Likes
Doh!  I forgot to post them.....Let me see if this works...Sorry, I Don't have sound files.
(Edited)
Photo of Jim    W3IPO

Jim W3IPO

  • 20 Posts
  • 4 Reply Likes
I am seeing the identical signal: same frequency. Peaking a -110 dbm in Alabama on a 20m simple dipole.
Photo of Ken - NM9P

Ken - NM9P, Elmer

  • 3875 Posts
  • 1179 Reply Likes
The two solid traces/spikes that bracket the pictures are local RFI. The rest is the signal in question. It is very curious. At first I thought it was my Uverse internet router or TP-Link gigabyte switch, but now am sure that it is "out there!"
Photo of Stu Phillips - K6TU

Stu Phillips - K6TU, Elmer

  • 642 Posts
  • 256 Reply Likes
It is  an Over the Horizon Radar believed to be from Iran.  Its been reported by the folks in IARU Region 1 and has been confirmed heard in the US and in South America.

Stu K6TU

PS: I'm an Intruder Watch volunteer and the note re this signal was in my email this am.
Photo of Ken - NM9P

Ken - NM9P, Elmer

  • 3872 Posts
  • 1177 Reply Likes
Stu, while you are at it, please report an idiot CBer on 27.025who calls himself the "Number 7 on the Westside"  He was literally 3 MHz wide!  I found him while trying to scan for a station putting a very distorted and unintelligible signal about 21.204 who was about 10 KHz wide.  I thought it might be harmonics or inverted spurs from a station on 10 meters.  Then I found this guy!  The widest signal I have ever seen on CB.  I wouldn't care much what happens down there, except his spurs are even getting into the 10 Meter band!  He is apparently winning a bandwidth war with the "Swampdog" who is about 100KHz wide.  
Photo of Stu Phillips - K6TU

Stu Phillips - K6TU, Elmer

  • 642 Posts
  • 256 Reply Likes
Best thing is to call the OOC (Official Observer Coordinator) for your ARRL section - their name and contact information should be in QST.

They can gather information and make sure that (eventually) the FCC will get in the loop - it will have to be a persistent offender to get actioned but if it is, it will be!

Stu K6TU
Photo of Ken - NM9P

Ken - NM9P, Elmer

  • 3875 Posts
  • 1179 Reply Likes
They are still on at 15:11Z
One signal extends from about 28.570 to 28:630 with spurs out to 28.660
The shorter, responding tone is wider, extending from about 28.540 to 28.660 with lighter spurs detectable from 28.525 to 28.700

Maximum signal strengths on my 160 Offset Fed Dipole at 38 ft have reached as high as -92 dBm.

Can anyone with a steerable antenna get a fix?

Ken - NM9P
(Edited)
Photo of Tim - W4TME

Tim - W4TME, Customer Experience Manager

  • 9043 Posts
  • 3434 Reply Likes
I see the same in NC.  S6 on peaks
Photo of George Molnar, KF2T

George Molnar, KF2T, Elmer

  • 1529 Posts
  • 541 Reply Likes
Well, nice to know there's prop to Iran. Now we need some operators there. Especially ones who LoTW QSL!
Photo of Sergey, R5AU

Sergey, R5AU

  • 802 Posts
  • 96 Reply Likes
Listening the same signals on 10m with s5-s9, on 12m with s5-s9

on 17m with s4-s9
Can just confirmed that this is signal from over horizon system
(Edited)
Photo of W5XZ - dan

W5XZ - dan

  • 562 Posts
  • 83 Reply Likes
any old timers remember 'The Woodpecker'?  I even heard it once on the am bcb !!

73, w5xz, dan
Photo of Ken - NM9P

Ken - NM9P, Elmer

  • 3872 Posts
  • 1177 Reply Likes
That's why my IC-745 (ca. 1985) had a two-position noise blanker and why I modified the noise blanker on my TS-850 (ca. 1993) , which had two positions that didn't work until modified.  it was brutal!  But at least it was a constant tempo and width, so it could be blanked.
Photo of Jim    W3IPO

Jim W3IPO

  • 20 Posts
  • 4 Reply Likes
Here is a link to the signals monitored by the IARU:

http://www.iarums-r1.org/iarums/latest.pdf
Photo of George Molnar, KF2T

George Molnar, KF2T, Elmer

  • 1529 Posts
  • 541 Reply Likes
Another good one on 10m. That band gets so much "attention" from interlopers, eh?