7.040 Digital Signal?

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  • Question
  • Updated 10 months ago
  • Answered
I've noticed, recently, that there is some sort of digital signal on 7.040.  It seems to be going away at night.

I'm curious if anyone else is hearing this.  If not I may have some sort of local issue, or possibly a device in the house or shack causing the signal.

If anyone could confirm they are hearing it I would appreciate it.

Thanks

Rich - N5ZC
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Rich - N5ZC

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Posted 10 months ago

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Photo of Mike  W1BFA in Maine

Mike W1BFA in Maine

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I can hear it here in Maine at about an S5 with QSB, if it's the same one.  It starts and stops and is  modulated but I don't recognize it.
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Mark - WS7M

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There is one of those mail digital services (WinLink?) on about 7.030.  It puts up a wide digital signal at times for me.  
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K3ZJ - Dave

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One possibility is to try to match one of the patterns here:http://www.arrl.org/sounds-of-rfi
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Bob- W5TX

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I have heard this signal (very loud) and it appeared to have a time modulation, one pulse every second. Others have told me that it seems to come from South (they were in N Central U.S.) which may explain the strength here in TX. Modulation disappeared during the NAQP contest on 1/13 local with the signal disappearing completely at around 7pm local.
Hmmm, very strange.
Bob W5TX
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Rich - N5ZC

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Glad I'm not the only one hearing it.  That at least rules out a local man made source.

Guess we'll just have to deal with it.

Rich - N5ZC
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Tim Ellam

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A good source for information on in band unwanted signals is the IARU Monitoring System coordinated by DK9OM and HB9CET . The IARU R1 website has a link to the MS Newsletters and although R1 focused, there is good information for North America http://www.iaru-r1.org/index.php/monitoring-system-iarums

I note there is reference to a uncoordinated beacon at 7040.

Tim VE6SH

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Donald, VE2HJ

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Hi,

These are WSPR signals. In the WSJT-X suite choose WSPR .Select the 40m frequency .

73

De Donald, VE2HJ



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Rich - N5ZC

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Thanks Donald,

I fired up WSJT-X and chose WSPR.  Sure enough, the signals were decoded.

I had never tried WSPR, so I had no idea what to listen for.

Rich - N5ZC
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Reggie-k6xr

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Yes! it is always there here in California where I live. 7.040, always pretty strong.
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Bob- W5TX

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don't believe this is a WSPR signal.  Sounds like WWV except no voice and is very wide on ticks.
If it's a beacon it's very strange.  Spectrum was one second pulses.

Bob w5tx
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Stan - VA7NF

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WinLink HF hubs are common on 40M.  They idle with short (<1 second) bursts and read/write data when another station answers.