Interference

[flaw101]

Have any of you experienced this type of interference on hf? Any ideas what it might be?

https://www.dropbox.com/s/j3t1avdv6uhdxs7/Video Sep 09, 5 45 34 PM.mov?dl=0



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[ab5r]

Disconnect your antenna and see if it still there.

 

[zz0468]

I've heard noises like that coming from cheap switch mode power supplies, wall warts, cellphone chargers etc.

 

[majoco]

If you have a good antenna attached to the radio, don't forget we are having massive solar interference at the moment.

 

[krokus]

I have heard noise like that from poor connections in the antenna feed line. Check for corrosion and/or water in the connections and coax.

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[flaw101]

I have heard noise like that from poor connections in the antenna feed line. Check for corrosion and/or water in the connections and coax.

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Thanks guys. It goes away when I disconnect antenna. I'm south of Jacksonville FL, so maybe when we lose power and go to generator it'll go away. After the storm, I'll start isolating circuits to try and find the culprit. I'll check antenna connections then too


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[ab5r]

Good Job. That eliminates the radio as being the problem. Good luck with your search.

And, most of all, God Speed with Hurricane Irma!

73

 

[WA8ZTZ]

Sounds like it's that HF Over the Horizon radar that covers most of 20 meters, IIRC the call letters are D0G.

Good luck with Irma.

 

[wrath]

I am the king of feed line chokes ,I put them on everything ,they are pretty cheap and can only help .

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[flaw101]

I am the king of feed line chokes ,I put them on everything ,they are pretty cheap and can only help .

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Ok. So no power here. Running off generator and no interference. Very quiet on the bands. This will be an interesting investigation.

On side note, fence damage from wind, yard is a pond, but we're doing well. Thanks for your thoughts!


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[WA8ZTZ]

Good to hear you got through the storm in fairly good shape.

Enjoy the quiet bands and best DX !

 

[wrath]

I have twelve sealed AGM batteries backing up my station could you send a storm my way , the quiet would be awesome,i ueed yo live inthe middle of nowhere unfortunately i am on the edge of the noise capital of the universe according to my radios s meter, usually around 5 to 7 over , but i have a friend about 15 minutes up the road that has no noise what so ever, I gave him one of my rigs to use in his shack so we vould both work the bands.

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[kk6jtl]

Sounds like my old dishwasher motor or old clothes washer drum motor.

 

[flaw101]

Figured it out

Finally figured out the source. A ceiling fan. The newer fans apparently use speed control electronics that cause this interference. And this particular fan is located directly below my hexbeam. Guess the xyl will have to sweat it out while I'm operating. Watch out as it can be tricky finding sources like this. It was transmitting through the house's electrical wiring, so my portable HF receiver was seeing it strong at every outlet in the house.

 

[JamesO]

A lot of RFI and noise is usually locally generated often as you have found in your own home.

I find the fastest way to isolate the problem is to power the radio on battery/DC if possible, then start flipping circuit breakers in the house until everything is powered off.

My battery powered electric shaver would make all sorts of VHF pulse noise once the battery was charged and the charger/shaver went into some strange pulse mode. I just need to make sure I always unplug the power cord once the shaver is charged.

You just never know what is going to make noise and it is often what you least suspect as a problem.

Glad you finally figured out what the source is, might be time to upgrade the fan.

 

[flaw101]

Ceiling fan RFI

So, I have two of these fans in the house; one in the family room, one in the master bedroom. Both cause the RFI. They are fairly new with the wireless remotes. I notice when I power them down, the RFI continues until the completely stop spinning. Using the portable receiver, it appears the house wiring is acting like an antenna. Besides replacing the fans, any ideas on anything I might be able to do at the fans to choke off the RFI? Can't find anything on the web.

By the way, the interference shows up on multiple HF bands.....20, 40, 30

In the mean time, I'll experiment with choking the antenna feedline.

 

[prcguy]

At HF its usually the wiring acting as an antenna that radiates the noise. You might try one of these in the ceiling on the power leads (Romex?) that feeds the light and as close to the light as you can get it. You will need about a foot and a half of slack in the wiring to wrap 5 turns. 2X31-1081P2 - Amidon

For HF down to maybe 80m you would need to have the wires pass through the core about 5 times. Bare wires will fit but Romex may fill up the hole before you get to 5 turns. That may cut the noise down to an acceptable limit but it should at least reduce it some.

Here is a filter you can possibly build into the fan housing and this should fix most anything that is producing HF noise and radiating it via the power lines. Grow Light Ballast

I have lots of ferrite cores here mostly to keep RF from getting into speaker cables and to keep security cameras from making noise in the VHF spectrum. I also had to add ferrite cores to about a dozen recessed ceiling lights when I changed over to LED bulbs that made a lot of noise in the VHF band. Fortunately I've had no big issues with HF noise here yet.
prcguy

So, I have two of these fans in the house; one in the family room, one in the master bedroom. Both cause the RFI. They are fairly new with the wireless remotes. I notice when I power them down, the RFI continues until the completely stop spinning. Using the portable receiver, it appears the house wiring is acting like an antenna. Besides replacing the fans, any ideas on anything I might be able to do at the fans to choke off the RFI? Can't find anything on the web.

By the way, the interference shows up on multiple HF bands.....20, 40, 30

In the mean time, I'll experiment with choking the antenna feedline.