Wideband noise example

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  • Updated 1 year ago
Here is a link to a Youtube video describing a wideband noise source at my QTH and how it interacts with various DSP controls on my 6500..

https://youtu.be/hK2oLIf3gIk

Ken - NM9P
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Ken - NM9P, Elmer

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Posted 1 year ago

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Milen KG2C

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Hi Ken, I really enjoyed watching the video. I hope you manage to do something about the equipment causing that kind of noise.
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Kevin N9JKP

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Ken,

From your video I understand that you believe you are sensing the direction of the interference but I also assume you have been able to pull your main breaker, and run your computer and the radio off battery so you have ruled out anything on your side of the utility's meter.

Kevin N9JKP
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Andy - KU7T

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Kevin,
I am interested in your comment about running computer and radio off battery. Can you elaborate what it takes to do that?  I would love to do this, as I suspect some switching supplies are bad.  I am sure I could shed a few dBs by doing this...

Laptop has a few hours of power, so it is mainly the radio plus 12V control supply for antenna switches...
Would be nice to walk around in the house and see the changes, so Wifi would be good.  Or laptop would have to stay sitting next to radio...
Suggestions?

Thanks
Andy
KU7T
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Kevin N9JKP

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Andy,
I suggested this for seeing if the problem was within the house.  Whilst I control my Flex from a large desktop computer, I have a laptop which I could use.  As for the radio, it certainly can run off a battery, I have a large UPS which would run it for quite awhile on its batteries.

I have no hardwired connection between my computer and the flex, I have a short fiber cable jumper between the Flex and my computer.  To power the Flex I use a linear power supply, I don't have switching power supplies except for the computer itself.  By far the loudest "noise" in my shack are the cheap fans in the Flex.

I guess if the noise was within the house then being able to walk around with the laptop as you turned stuff off and on might be helpful but a radio tuned to a clear AM channel has always worked well for me.  I have also used a handy talkie with the Squelch wide-open to find noises.  I used this method which found a horribly noisy L.E.D. porch light.  
73,
Kevin N9JKP
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AA0KM

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First time having this issue I been having the same problem for little over month and a half.

First time having this issue this bad in the city.

Just when you think you have it figured out it quits.

I have switched around power supplies.

I have went to DC power and house power off.

I thought I had it timed when it would start then over period of day`s it would fool me and start ealier or later.

It stays in the same places on the panadapter.

Like chasing ghosts.

It seems stronger in the daytime early afternoon on 10-40 meters.

I get it early evenings on 80 meters and sometimes 160 meters then it most times goes away on 80 meters but it might stay on 40 meters till late.

Thought someone`s TV but it is random.

I thought about neighbors work schedules then again noise random.

(((Some nights and days no issues))

Very very random.

Best guess dirty signals on power lines or bad power transformer somewhere.

Earlier today 09-11-2017  from about 2:pm till 6:pm CDT had the noise on all bands.

(SEPT 11-2017 after 7 pm all bands quiet central usa)

Most signals are about S-7 never any stronger on inverted Vee at about 35ft center.

I took old 9 volt AM hand held radio and tons of noise on the all the cables (attached) to my house.

I have line Isolator right after the 4:1 balun never been an issue till last month and a half randomly.

Only solution looks to be the following or bad radiating power lines or something happens, rain ,wind or destruction. :)

 Looking at timewave ANC-4 or MFJ-1026

http://www.mfjenterprises.com/Product.php?productid=MFJ-1026

https://timewave.com/product/timewave-anc-4-antenna-noise-canceler/

Ken your not the only one! Hope this all goes away soon.

At wits end on this one. 73 All  Good luck!

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AA0KM

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I will get pictures another time. All bands are normal at the moment.
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AA0KM

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Just a thought occurred while thinking. Where I live we are now co-op with lot of utilities grid tied with solar now and wind power as well. I don`t know any of the details how this all works but I imagine this has been grid tied stuff for a few years now so nothing new but is something to think about I suppose.


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Rich McCabe

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Anyone have suggestions for a good antenna for noise tracking?  I bought a Tecsun SW receiver for this purpose but have yet to come up with a decent directional antenna to use with it.  I would like to be able to use it inside the house tracking local stuff as well.

Ken, that looks awful!

73,
Rich
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AA0KM

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09-12-2017 4:30 PM


4:30pm

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AA0KM

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