Interference... What could it be?

[csuh13]

I'm getting this weird popping noise interference on all SW freqs. It's new, and I've added nothing new in the house electronically. I made a quick recording (see YouTube link below,)

Does this sound familiar to anyone?

http://youtu.be/RDvAbUgT1Ys

 

[k9rzz]

You've got it set at "private". We can't see it.

 

[csuh13]

oops...

Fixed that. It is public now. Sorry!

 

[Token]

Has anyone around you put up a new electric fence or pet control fence? Alternately, was the radio connected to an external antenna, and what are the chances the wind was blowing something to make contact with the antenna?

T!

 

[SCPD]

Does this sound familiar to anyone?

Sounds like an electrical spark. Could be from nearby powerline and/or anything that uses mains power such as outdoor light, x-mas lights, etc.

 

[Boombox]

Sounds like you might have some Christmas lights that blink somewhere near by. I get that sound on my radios from several blinking C7 Christmas lights in my yard.

 

[csuh13]

It's a dipole on my roof, not under the power line. The only electric fence in the neighborhood is in my backyard, but this popping happens 24/7, and the fence is only energized dusk to dawn.

 

[Boombox]

I still think the popping sounds like blinking Christmas lights -- it sounds like mine do on my radio. If you don't have a blinking Christmas light in your house, perhaps a close neighbor does. I hear the popping from mine at least twenty five feet away, and that's on a whip antenna.

RE: your Dipole & Powerlines: your antenna doesn't have to even be close to powerlines (or a noisy transformer) it to pick up powerline buzz, because the power company's transmission wires act as RFI transmitting antennas, and when it occurs they can radiate RFI more than a block away.

But what I'm hearing in your recording doesn't sound like powerline RFI. More like blinking Christmas lights.

 

[jtcase]

Probably best to start with the most basic step. Make sure your Grundig has batteries and can run without AC. Turn on the radio, on batteries, and make sure the interference is still there. Then pull the master fuse/breakers to the house. When you are sure that all AC power to the house is disconnected, see if you still have the interference. This is a good starting point to see if you have the problem, or if it is external to the house. If you still have the interference, make sure it is nothing in the house still running on batteries before focusing your attention on the outside.

If the interference is gone with the power cut, it is pretty easy to track down the source. Restore the power one fuse/breaker at a time until you hear it, then cut everything else except that line. Then find out what it feeds, and go outlet to outlet to see who the trouble maker is.

If the source of the interference proves outside, then it will be a lot more difficult to find. I have been very successful in "pole hunting" to find noisy poles and getting the power company to fix them. I am totally noise free for the first time in years. The only problem is that noise does not sound like a power pole problem.

If you do have to go outside, a good AM radio makes an excellent direction finder.

Good luck.

73, John

 

[csuh13]

Umm...

Well, shut off house power and the pops are still there on battery (It's a Grundig Sattelit 800, BTW) and I can hear the pops when walking around with both my Grundig mini 100 and my RS DX-398. I get the same pops when walking around outside my house, 2 houses in each direction. No change in strength of pops... Ack!

 

[k9rzz]

To be sure it's not the radio itself, can you hear it on another? LIke your car radio?

 

[jtcase]

I am inclined to agree that it sounds like a buried dog fence.

I bought a directional antenna from Arrow Antenna, tuned to the 2 meter band, and used first a Tecsun PL-660 and later a Yeseu FT-60R/E to track down the interference. Am and SW can travel miles along the power lines, but if you use a higher frequency the range is a lot smaller and easier to find walking around. On the Tecsun PL-660, I used the air band; around 139 MHz for this reason. Also, has to be set up in AM.

With a directional antenna it is much, much easier to pinpoint the noise, but it can be down with an internal ferrite bar antenna as in your DX-398 using the MW mode. The Satellit 800 internal ferrite bar antenna is too short to get you a close in reading.

You may have to walk a few blocks, but you need to do this and try to triangulate the source of the noise. You should be able to null the clicks by rotating the loop stick, and get a general direction. Sounds harder than it is. I have done it a lot.