5punk

Recently (last 3 weeks) I have noticed my speakers (Logitech Zxxx) have started picking up some French radio. It plays while there is sound coming out via my PS3 or my Skybox and it's really bloody annoying. It also plays if there is no input from any other device and I just switch them on.
It seems to have random bursts of static and then prolonged playing of the radio. Today it switched to Taiwan International and it is now stopping me from enjoying any tv watching or gaming on my PS3 and I have no idea how I can stop it.
Any ideas would be appreciated.

Wrap them in tin foil?

Ok I'll try this first. Wil let you know what happens.

Dog Pants wrote:Wrap them in tin foil?

That wouldn't work would it? not least because you can't get tin foil any more, and IIRC aluminium foil doesn't work that well as shielding.

What you need is copper foil, and earth one end of it.

I'll give it a few days to see what happens. I have discovered the frequencies of the stations i'm picking up, 88mhz and 75.66mhz.

Well I wasn't being particularly serious, although cables do sometimes come with foil shielding. Something somewhere is acting as an antenna though, although you probably already worked that out for yourself. Maybe the earth has worked loose on your speakers' shielding, or one of your cables is somehow picking it up. Are those stations FM? Googling the frequencies suggests they're in the right range. I never did work out how, when random electronics starts picking up radio signals, they managed to demodulate it.

Dog Pants wrote:Well I wasn't being particularly serious, although cables do sometimes come with foil shielding.

Indeed, but it's not aluminium

Dr. kitteny berk wrote:Indeed, but it's not aluminium

I'll give you that, I don't know what it's made of. It's silver and a pain in the tits when you're stripping cable.

Indeed, I think there's one made of plastic (I imagine embedded with copper or something) too, that's particularly annoying.

Not sure if they're FM I'm afraid. It's fine if I turn the volume up past a certain point but I cant have it that loud all the time.
Guess I'll have to make use of my headphones more often.

Well fixing it should only be a matter of finding out where the interference is getting in and stopping it. Might just be something as simple as moving a cable or plugging a connector in that's come loose. Hang on, you've not had new French neighbours with a big stereo and thin walls have you?

Dog Pants wrote:Well fixing it should only be a matter of finding out where the interference is getting in and stopping it. Might just be something as simple as moving a cable or plugging a connector in that's come loose. Hang on, you've not had new French neighbours with a big stereo and thin walls have you?

That would make a good comedy sketch for a rather niché market.

You could build a Faraday cage around the speakers as well, just make sure the antenna is inside. That way you don't need to fuck around with foil. A nice cage made out of copper looks good as well.

Alternatively you could move inside a mountain.

Coming to think of it if you have absolutely no clue where the problem is, you can use the cage to determine it

Nuke France

Build a giant Faraday cage, and live in it.

Also nuke france.

I know fuck all about anything, but wouldn't sticking some ferrite chokes on the cables help? Or is that just to cut down rf noise?

Joose wrote:Build a giant Faraday cage, and live in it.

Also nuke france.

But aluminium foil might do the trick. I have used alu foil tape successfully for shielding cables before, but not had interference from radio (this is prob LW not FM unless you live in dover or something)

Some questions to help try and narrow it down:

Have you got any (new or changed?) runs of cable that could be acting like an antenna? (long straight or possibly coils?)
Is it coming out of all of the speakers? (and are they surround or 2.1?)
Does it happen with different input sources or just PS3 & Skybox?
Have you tried earthing the ground connector of the input cables?

My logitechs have done this for ages. The shielding is weak to non-existent on the satellite speakers, I too wondered about the demodulation part, especially given the fact that the volume control tunes to different radio stations.

I had a half arsed hunt for loose wires but now I just punch them and scream a bit when they start taking french/russian/italian/german at me.

ProfHawking wrote:

But aluminium foil might do the trick. I have used alu foil tape successfully for shielding cables before, but not had interference from radio (this is prob LW not FM unless you live in dover or something)

Some questions to help try and narrow it down:

Have you got any (new or changed?) runs of cable that could be acting like an antenna? (long straight or possibly coils?)
Is it coming out of all of the speakers? (and are they surround or 2.1?)
Does it happen with different input sources or just PS3 & Skybox?
Have you tried earthing the ground connector of the input cables?

I live nr Bath so nowhere near Dover.
I do not have any new cables and the longest distance they go is about 1.2m.
It comes out of both speakers and they are 2.1 with a hardwired sub.
It happens when sky and/or the PS3 is on and even if I unplug (mains) both it still broadcasts.
I wouldn't know how to earth the ground connector.

If its just 2.1, the input cable should look something like this:
Either a headphone style jack, or a pair of phono connectors.
excuse the shitty drawing:


I am thinking that the PS3, SkyBox and Speakers are all double insulated, and therefore their mains cables only have live & neutral power and no earth and are therefore just "floating". Are all of the leads/connectors 2 pin?
There is a lot to be said for grounding things properly, and if possible you could try that, but it might be a bit fiddly if non of the appliances are designed to be.