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Author Topic: Very Strange Alarm Noise  (Read 4099 times)

Offline PresentedIn4D

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Very Strange Alarm Noise
« on: August 16, 2010, 0104 UTC »
http://www.youtube.com/watch?v=vxcB9YMMjQQ
What could this possibly be? I'm currently in Jacksonville, FL, and this is the first time I have ever heard this. Is this just some sort of beacon, or something different? Thanks.
Syracuse, NY // FN13ua
40m Doublet + WiNRADIO Excalibur / Kenwood TS-2000
qsl @ presentedin4d at gmail . com

Offline SW-J

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Re: Very Strange Alarm Noise
« Reply #1 on: August 17, 2010, 1502 UTC »
http://www.youtube.com/watch?v=vxcB9YMMjQQ
What could this possibly be? I'm currently in Jacksonville, FL, and this is the first time I have ever heard this. Is this just some sort of beacon, or something different? Thanks.

I don't detect much fading on the signal (that may be a little difficult to tell from the recording on my end though). Fading, to put it succinctly, means distance.

If it's present with the same signal strength 24 hrs a day it's a) probably something in the house or b) probably something in a neighbor's house.

Edit: Spelling!
« Last Edit: August 17, 2010, 2045 UTC by SW-J »
o Icom IC-756ProII, ProIII, Alinco DX-70, Kenwood TS-680s
o WinRadio G303e, Degen/Kaito 1103/DE1103, Stoddart NM-25
o 1/2 wave 80m Dipole used with several tuners
o Tuned loops from 2' thru 16' diam. capable of 160m thru 10m

Offline PresentedIn4D

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Re: Very Strange Alarm Noise
« Reply #2 on: August 18, 2010, 1355 UTC »
http://www.youtube.com/watch?v=vxcB9YMMjQQ
What could this possibly be? I'm currently in Jacksonville, FL, and this is the first time I have ever heard this. Is this just some sort of beacon, or something different? Thanks.

I don't detect much fading on the signal (that may be a little difficult to tell from the recording on my end though). Fading, to put it succinctly, means distance.

If it's present with the same signal strength 24 hrs a day it's a) probably something in the house or b) probably something in a neighbor's house.

Edit: Spelling!
Hi,
The thing is, it is not 24/7. That was the first and last time I heard it. However, last night, I heard a signal on a lower frequency that was similar to this, but it had more fading, less clarity, ect.
Syracuse, NY // FN13ua
40m Doublet + WiNRADIO Excalibur / Kenwood TS-2000
qsl @ presentedin4d at gmail . com

Offline SW-J

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Fourier Analysis of "Very Strange Alarm Noise"
« Reply #3 on: August 18, 2010, 1617 UTC »
http://www.youtube.com/watch?v=vxcB9YMMjQQ
What could this possibly be? I'm currently in Jacksonville, FL, and this is the first time I have ever heard this. Is this just some sort of beacon, or something different? Thanks.

I don't detect much fading on the signal (that may be a little difficult to tell from the recording on my end though). Fading, to put it succinctly, means distance.

If it's present with the same signal strength 24 hrs a day it's a) probably something in the house or b) probably something in a neighbor's house.

Edit: Spelling!
Hi,
The thing is, it is not 24/7. That was the first and last time I heard it. However, last night, I heard a signal on a lower frequency that was similar to this, but it had more fading, less clarity, ect.


Let's analyze this signal as far as 'content'. It sounds kind of line-frequency related raspy, but let's run through the analysis and see what that shows.

Let's first take one 'rep rate' (repetition rate) of a group of pulses like this:


     


and then we will do Fourier decomposition (Fourier Analysis) which looks at the frequencies making up the signal.

When we do this in Sound Forge, we have this:

     


Notice we have this kind of relationship between spectral components and 60 Hz line related components:

Freq
 Peak  x60Hz
 ----  ----- 
 360     6
 900     15   15 x 60  Hz
 1800    30   10 x 180 Hz
 2700    45   15 x 180 Hz




I would have to consign this to the category of something line-related (AC power line related) ... could not of course say exactly what, but, probably not over-the-air mil or even civilian comms ...

« Last Edit: August 18, 2010, 1659 UTC by SW-J »
o Icom IC-756ProII, ProIII, Alinco DX-70, Kenwood TS-680s
o WinRadio G303e, Degen/Kaito 1103/DE1103, Stoddart NM-25
o 1/2 wave 80m Dipole used with several tuners
o Tuned loops from 2' thru 16' diam. capable of 160m thru 10m

Offline PresentedIn4D

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Re: Very Strange Alarm Noise
« Reply #4 on: August 18, 2010, 1804 UTC »
Ah, well, that clears it up. Many thanks, very interesting. I would have never guessed to analyze it in that way. So, you're most likely correct, it must be civilian electronics.
Syracuse, NY // FN13ua
40m Doublet + WiNRADIO Excalibur / Kenwood TS-2000
qsl @ presentedin4d at gmail . com

Offline SW-J

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6959 thru 6970 Strange Alarm Noise
« Reply #5 on: September 02, 2010, 2336 UTC »
Ah, well, that clears it up. Many thanks, very interesting. I would have never guessed to analyze it in that way. So, you're most likely correct, it must be civilian electronics.
Hmmm ... the plot thickens ...

I observed a signal like this, add: exactly like this, noted initially last night starting at 6959 kHz (while looking for pirates using a Degen/Kaito model 1103 portable) and over a few minutes it had moved up to 6961 ... then it was about 6964 ... and finally as high 6970 kHz after 10 minutes or so! ... and it had FADING on it, so, it was probably ionospherically propagated ... at times it completely faded out, then came back in ... weird ...

Sounds exactly like the signal PresentedIn4D has in his video ...
« Last Edit: September 05, 2010, 0028 UTC by SW-J »
o Icom IC-756ProII, ProIII, Alinco DX-70, Kenwood TS-680s
o WinRadio G303e, Degen/Kaito 1103/DE1103, Stoddart NM-25
o 1/2 wave 80m Dipole used with several tuners
o Tuned loops from 2' thru 16' diam. capable of 160m thru 10m

Offline SW-J

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Re: Very Strange Alarm Noise
« Reply #6 on: September 08, 2010, 1136 UTC »
Radio Marti - traced this 'noise' to coincidence with the jamming on Radio Marti on 7405 kHz

  http://www.google.com/search?hl=en&client=opera&hs=Yxy&rls=en&q=radio+Marti+7405&btnG=Search&aq=f&aqi=&aql=&oq=&gs_rfai=


Tracking the alarm 'buzzer' last night:

  http://www.youtube.com/watch?v=OzSgjzDlIgo



PS It appears PresentedIn4D has removed his vid, but I have about 43 seconds of audio from his video I will have to post ...

« Last Edit: September 09, 2010, 2052 UTC by SW-J »
o Icom IC-756ProII, ProIII, Alinco DX-70, Kenwood TS-680s
o WinRadio G303e, Degen/Kaito 1103/DE1103, Stoddart NM-25
o 1/2 wave 80m Dipole used with several tuners
o Tuned loops from 2' thru 16' diam. capable of 160m thru 10m

Offline SW-J

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Strange Alarm Noise - the buzz-buzz signal
« Reply #7 on: September 10, 2010, 0154 UTC »
Logging 'the buzz' tonight:

9-10-2010

0140z (8:40 PM) CDT 6941 kHz  7365 still jammed

0147z - 0148z (8:47 PM) buzz heard btw 6940 to 6946 kHz

0157z 6939 - 6941 kHz, 7365 kHz still jammed, 7405 kHz nothing on that frequency

0208z Not finding the buzz-buzz signal ...

0330z About 6964 kHz

9-13-2010 0202z Chased this buzzing from 7097 to 7110 kHz over about 10 minutes tonight ... drifting/wandering pretty bad ...

9-13-2010 0222z On the Icom was able to put the 'jammer' at 7365 (rcvr tuned to 7356.5) on 2nd VFO with wanderer on 1st VFO and switch from one to the other ... I get the same 'buzzing' sound from both the jammer and the wandering signal ...

  With captions:  http://www.youtube.com/watch?v=V_t9qv3fcmY


9-13-2010 0305z Broadcast station left 7365 kHz and one jammer left too, but another one stayed ... and the one that stayed does a slower 'galloping' buz-buz ... have vid and should post ...

« Last Edit: September 13, 2010, 1412 UTC by SW-J »
o Icom IC-756ProII, ProIII, Alinco DX-70, Kenwood TS-680s
o WinRadio G303e, Degen/Kaito 1103/DE1103, Stoddart NM-25
o 1/2 wave 80m Dipole used with several tuners
o Tuned loops from 2' thru 16' diam. capable of 160m thru 10m

Offline PresentedIn4D

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Re: Very Strange Alarm Noise
« Reply #8 on: October 12, 2010, 2329 UTC »
Yes, I removed the video. I did this because I thought it was unnecessary now.
So, we're now changing this idea or something?
Syracuse, NY // FN13ua
40m Doublet + WiNRADIO Excalibur / Kenwood TS-2000
qsl @ presentedin4d at gmail . com

Offline SW-J

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Re: Very Strange Alarm Noise
« Reply #9 on: November 15, 2010, 0001 UTC »
Yes, I removed the video. I did this because I thought it was unnecessary now.
So, we're now changing this idea or something?

Yeah, based on new observations from the field ...
o Icom IC-756ProII, ProIII, Alinco DX-70, Kenwood TS-680s
o WinRadio G303e, Degen/Kaito 1103/DE1103, Stoddart NM-25
o 1/2 wave 80m Dipole used with several tuners
o Tuned loops from 2' thru 16' diam. capable of 160m thru 10m