Interference

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NJ3H
Posts: 21
Joined: Wed Aug 19, 2020 5:35 am
Location: Redmond, Oregon USA

Interference

#1

Unread post by NJ3H »

Greetings,

I could sure use some help trying to identify as shown in the attached pictures. This interference occurs in the 2 mhz, 7-10 mhz, and 16-20 mhz bands and to a minor amount elsewhere on HF.

I have had this problem before. I have walked the neighborhood with a portable Sony SW receiver. On house (3 away from me 250 feet) seems to have interference when I am in their yard. The young guy basically refuses to help out. I have talked to him in the past very nicely. He won't even answer the door.

One picture is from SDR Console using my Elad S2. The other picture is using the Perseus. my antenna is a 1-meter diameter Wellbrook loop in my back yard.

I have shut down the power to the house at the panel board and used a powerpack to provide power to the necessary components. I still have the interference as indicated on the attached pictures. I do have ferrites on the antenna cables and power cables.

Anyway, I really want to determine what is causing this interference.

Regards,
George, NJ3H
Redmond, Oregon USA
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SDR Console
SDR Console
Perseus
Perseus

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G0OFE
Posts: 435
Joined: Thu Aug 06, 2020 7:33 am
Location: Sunny Sunny Bournemouth IO90BR
Contact:

Re: Interference

#2

Unread post by G0OFE »

Looks like a psu of some sort, possibly a cheap charger.

Unfortunately, if the geezer wont even engage, you're rather stuck with it until/unless it disappears.
Jim, Bournemouth IO90BR
Image

Mag loop Simon
Posts: 50
Joined: Wed Aug 19, 2020 11:29 am

Re: Interference

#3

Unread post by Mag loop Simon »

Cheapo smpsu..

Phone charger etc

Try to null out with your loop..
If that fails build/ buy a noise phaser

If all else fails move to a ship on the sea..sorry thats not ment to be nasty..but welcome to 2020..
I live in london..you get rid of one source and another appears..almost daily..

Noise like that can come from to name a tiny few..
Chargers.
Led lighting
Fridge
Cooker
Washing machine
Tv
Cheapo pc display
Wifi
Etc..

Dont make enemy of your neighbours...that is not good..complaints against you will start to come in..

Good luck..

Max
Posts: 859
Joined: Thu Aug 13, 2020 9:47 am

Re: Interference

#4

Unread post by Max »

Yep, thirded.... cheap far-East manufactured noisy SM power supplies of any sort of which there are loads in close proximity either in your own home or those of neighbours as they come with practically every plug-in device these days.

Also poorly filtered UPS of some sort can be awful culprits. I had a Belkin unit 1200 VA unit and it was atrocious. Now replaced with CyberPower unit which is totally RF silent (actually I now have two they are so good).

Is it there day and night? If only daytime, then possibly solar power inverters?

Good luck

Max

Mag loop Simon
Posts: 50
Joined: Wed Aug 19, 2020 11:29 am

Re: Interference

#5

Unread post by Mag loop Simon »

Thing is..unless the noise is from your house the chances of fixing it are at best poor..

So you have to work at your rx end..

You have a loop.try to null it out. Run filters in your power to rx..( incase some is mains bourne.)
Add common mode choke to your loop coax..
Noise canceller..I have a homebrew one..easy to make..works wonders..
Typically i have a s2-3 noise floor on 160-40m with my tx antennas..( abit more on the elad as I cant switch off the rf preamp/ or adjust gain..less on the hl2...) I live in london..lots of chokes!! Everything in house switch mode has one..
antennas have chokes..mains to shack has etc..
Without above not worth switching on rig..

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