rf interference with speakers

[Red Squirrel]

My speakers seem to pickup a radio station and I can actually hear the radio through them. They have to be plugged into the computer for it to work, but it does it with those speakers while it did not with my old set. It's a good station at least. Is there a way I can block this other then getting a different sound card or speakers?

 

[Zepper]

Try running the wire from the PC to the speakers (Line Out) thru a ferrite ring (wrap once around the rim of the ring) and see if that helps. Radio Shack used to carry them but IDK if they do now. Looks like they only have a snap together core now. It's too big for that input cable but you can tape it in place about an inch from where the cable enters the speaker.

You can also change the orientation of the cable. Aligned with the direction of the signal will reduce pickup while perp to the direction of signal will increase pickup.

Here are some more ferrites:

http://www.allelectronics.com/cgi-bin/category/235/Ferrites.html

.bh.

 

[Red Squirrel]

Is there a way to make such ring? I doubt I can buy that where I live. It does seem to be the cable acting as an antena though. I can make the sound vary when I move it around. At one point I had it setup so it was not picking anything up. It's a long unshielded cable and it was looped in an oval shape, if I squeezed on it, it blocked off the radio.

And this is an FM station too. Very odd. I've heard of various ways to pickup AM but FM is normally much harder.

 

[Zepper]

An individual usually can't make ferrite cores. allelectronics.com may ship to Canada.

.bh.

 

[Red Squirrel]

Another weird thing I forgot to mention is randomly I'll get a signal on the speakers, it's really hard to explain, kind of like feedback with some distortion then it cuts off. CB radio or something. I'd almost have to set a tape recorder near and wait till it happens. Seems to be at night more than day. I'll try to find a place that sells ferrite rings but I"m not ready to order from a US site not knowing if it will fix my issue or not.

Maybe it's aliens trying to communicate with me.

 

[Zepper]

Nah, it's Big Brother watching your every move! Since you fairly well proved that the line in was picking up the signal, a ferrite ring or snap-on should help quite a bit.

.bh.

 

[Leros]

Originally posted by: RedSquirrel
Another weird thing I forgot to mention is randomly I'll get a signal on the speakers, it's really hard to explain, kind of like feedback with some distortion then it cuts off. CB radio or something. I'd almost have to set a tape recorder near and wait till it happens. Seems to be at night more than day. I'll try to find a place that sells ferrite rings but I"m not ready to order from a US site not knowing if it will fix my issue or not.

Maybe it's aliens trying to communicate with me.

The distorting could be the signal from you cell phone. My cheaper, unshielded speakers would always buzz right before I got a phone call.

 

[Red Squirrel]

We do have a cell phone but it's never near the speakers (I've experienced what you said, when someone left their cell near the speakers). It's hardly turned on when it's in the house though.

I decided to put back my other speakers since it seemed to be worse, even quick changes in video such as going from dark to light would cause static. The older ones do have some interference but not as bad (just slight white noise), but unlike the new ones, I don't have to crank them loud enough to hear it. Guess newer is not always better. The new ones match with the TV downstairs anyway I can always hook them up if I get the proper adapters. I'll look into the ferrites if they still have issues downstairs.