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RF noise




 
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Detroit47
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N8QPC on your AM dial


« on: November 06, 2020, 03:52:02 PM »

 There is a huge internet cable running thru my neighborhood. It has all sorts of cans and gizmos on it. It will trash an AM car radio at evenly spaced intervals. It has harmonic all the way up past 40 meters. I can take pictures if any one is interested. If I lived next to it a AM radio would be useless as well as HF gear. I don't know how they can get away with this. I was thinking that I should log a complaint with the FCC.
Upon closer inspection I saw WOW tag on the equipment. Anyway it leaks RF  like a sieve. This can't be legal.


* 20201106_153644.jpg (2497.38 KB, 4032x2268 - viewed 93 times.)

* 20201106_153519.jpg (2079.45 KB, 4032x2268 - viewed 75 times.)
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W1NB
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« Reply #1 on: November 06, 2020, 07:24:18 PM »

The first picture appears to be of standard telco twisted pair splice enclosures. The second picture is a fiber optic splice enclosure. Itís possible that DSL carried on the twisted pair could be causing some interference, although Iíve never seen it generate what youíre describing. The fiber optic splice enclosure has no active electronics, only glass. Thereís no way any emission could be coming from it. The more likely source is the broadband coaxial cable. That cable carries fairly high level RF from about 5 MHz to, depending on the systems bandwidth, as high as 1 GHz. Most of that RF will be in the form carriers modulated with QAM or OFDM. From a spectrum signature standpoint, 64 and 256 QAM will look like 6 MHz wide haystacks. OFDM will have 25 KHz spaced subcarriers and can be as wide as 192 MHz per channel.

Leakage happens when there is an impedance breach in the line, usually caused by a break or heavy oxidation at a connection. Usually, though, a breach will cause major issues for the upstream RF, allowing significant ingress of noise and over the air signals. It generally results in modems dropping off line or extremely low speeds and timeout errors. The operators monitoring system should detect issues and maintenance techs will be deployed to track down the issue an repair it.
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Detroit47
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N8QPC on your AM dial


« Reply #2 on: November 06, 2020, 10:01:30 PM »

It has been like that for over a year if I drive any where along thst line. It will take AM 1400 off the air. I live about 3 blocks from it and I can hear it my reciver. I took my Drake Sw8 reciver in the car and checked it out. That is the noise source in my backyard
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Patrick J. / KD5OEI
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« Reply #3 on: November 07, 2020, 08:51:05 PM »

report it to the owners of those wires?
If they do nothing in a reasonable time, complain to the commercial radio stations being interfered with.
What a mess.
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Radio Candelstein - Flagship Station of the NRK Radio Network.
W7TFO
WTF-OVER in 7 land Dennis
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IN A TRIODE NO ONE CAN HEAR YOU SCREEN


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« Reply #4 on: November 08, 2020, 10:13:00 AM »

Welcome to IT construction practices in the real world. Tongue

Indeed, a mess everywhere!

73DG
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Just pacing the Farady cage...
W3SLK
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Just another member member.


« Reply #5 on: November 12, 2020, 09:11:07 PM »

That looks like some of the handiwork I have seen down in Colombia!
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Mike(y)/W3SLK
Invisble airwaves crackle with life, bright antenna bristle with the energy. Emotional feedback, on timeless wavelength, bearing a gift beyond lights, almost free.... Spirit of Radio/Rush
KA3EKH
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« Reply #6 on: November 13, 2020, 08:52:25 AM »

The FCC takes cable leakage seriously, every cable service provider has to file a form 320 with the FCC annually that certifies that they are not leaking. Although the FCC is obsessed with the aeronautical segments of the band 108-137 and 225-400 MHz any leakage is an issue.
Comcast is usually good about technical operations and maintaining their plant but a lot of the other operators can be real hacks.  But all of them know for certain that leakage and the FCC can add up to big fines.
Almost every company owned truck by cable operators caries a leakage detector receiver thatís set to detect a carrier thatís injected at the head end so if they drive by a leaking section they can identify and eventually repair it.
Notify the FCC directly at https://consumercomplaints.fcc.gov/hc/en-us and try entering it as a problem affecting radio, or call the cable operator directly although that can be often an issue trying to reach someone who understands what you are talking about but if you do reach anyone involved with the technical side of the plant you are doing them a favor.



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km6sn
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« Reply #7 on: November 13, 2020, 09:31:32 AM »

You will find it easily with this:

http://amfone.net/Amforum/index.php?topic=46262.0

believe me, IT WORKS!

search for a noise at VHF that sounds like your 1400 kHz noise.

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Detroit47
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N8QPC on your AM dial


« Reply #8 on: November 13, 2020, 03:50:40 PM »

I contacted WOW they own that trash. All I could do was talk to some Indian joker that wanted to know what was wrong with my service. They didn't seem to care what was going on with interference. As far as tracking down the exact source it ain't my problem. I am documenting the problem and will contact the FCC. I have had good results with them before regarding interference from a guy growing weed. They had me go thru Mike Gruber, W1MG ARRL EMC Engineer. I have Laura Smiths direct phone and email at the FCC. She said if I have any more problems to call or email. I am going to do so. I am also contacting the local AM Broad cash stations and inform them they are  being interfered with. I am going to make myself into a huge PITA that won't go away.

Johnathan N8QPC
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