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This is not supposed to happen

CPC do some fairly decent RFI filtered mains suppression distribution boards. If looking, though, watch out as many types only have 'spike' protection. Only some have RFI filters.
Interesting. Do you mean the main distribution for the whole house as in where the RCDs go or can you get these for particular sockets or circuits?
 
I mean the items where you can plug into a wall socket a (usually rectangular) line of sockets to let you connect a number of mains plugs into one wall socket. I'll see if I can recall a CPC part number of one of the examples I tend to prefer.

The do also sell RC filters you have to wire in yourself. But it tends to be easier for most people to buy one of the above as you just plug things in and don't need to worry about soldering mains leads safely, etc.
 
I mean the items where you can plug into a wall socket a (usually rectangular) line of sockets to let you connect a number of mains plugs into one wall socket. I'll see if I can recall a CPC part number of one of the examples I tend to prefer.

The do also sell RC filters you have to wire in yourself. But it tends to be easier for most people to buy one of the above as you just plug things in and don't need to worry about soldering mains leads safely, etc.
Thanks: that would be useful.
 
I couldn't find the ones I bought, but I got them mumble years ago, so may have been discontinued. However an example I found was

Phonapart CS929/BP

CPC order number PL09832

They have a variety of boards. But many tend to just offer "surge protection". i.e. They may have just stuck zdr voltage surge spike clippers between the wires to preven high voltage spikes from getting through. They tend not to be much use for stopping low level RFI. Indeed, they might invoke a surge *current* loop that then radiates *more* crap. So for real RFI rejection an RC filter makes more sense. Possibly combined with a ferrite block.

I've not tried the above example, though.

As I've said, you can also buy filters. But the best ones you tend to then have to DIY into a box with a pluglead and socket(s). So not advisble unless someone has the required experience with making up mains stuff.

That's reminded me that when I became a research student mumble decades ago our first steps in being 'trained' were:

A) A simple job to machine up on a lathe and mill

B) Building our own mains distribution block
 
That CPC unit looks like a Tacima, which can be had from Amazon a little cheaper - here. But a single inline one would possibly make more sense for active speakers.
 
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That CPC unit looks like a Tacima, which can be had from Amazon a little cheaper - here. But a single inline one would possibly make more sense for active speakers.
Yes I noticed that in the catalogue the Tacima is listed with the same part number.
http://www.easyflip.co.uk/CPC_Digital_Catalogue/?page=1894

My speakers both come off one plug, so that would be ideal. Don't know if they make a single filter -any idea Andy?

In any event I'm not sure I would worry too much about this unless I was sure it was coming down the mains. I have not ruled out direct transmission/coupling. In fact it seems more likely to me at the moment. I will try out Jim's speaker rotating (aka dancing) test.
 
This site contains affiliate links for which pink fish media may be compensated.
Yes I noticed that in the catalogue the Tacima is listed with the same part number.
http://www.easyflip.co.uk/CPC_Digital_Catalogue/?page=1894

My speakers both come off one plug, so that would be ideal. Don't know if they make a single filter -any idea Andy?

In any event I'm not sure I would worry too much about this unless I was sure it was coming down the mains. I have not ruled out direct transmission/coupling. In fact it seems more likely to me at the moment. I will try out Jim's speaker rotating (aka dancing) test.

You can try screening the offending speaker with something like aluminium foil to see if its RFI related. Just use a double or triple thickness and move it around the speaker.

Cheers,

DV
 
You can borrow my well thumbed example.
Annoying though, I am certain a man of your calibre will sort it out, have you tried reasoning with it ?
BW Keith

Well I think that when Pinback tried this there was a big explosion and he was instantly killed.

Cheers,

DV
 
My speakers both come off one plug, so that would be ideal. Don't know if they make a single filter -any idea Andy?

There are plenty of single filters from people like rs and cpc but most of them are just built into IEC sockets and designed to go inside products. This thing from MCRU might do the trick though: link.

But you need to do some fiddling about first to find out what the issues are. Twist your speakers as suggested, turn the lighting circuit off, run the speaker off an extension cable plugged into somewhere else.. you just have to be a bit methodical and patient and do some experiments. Best to find the source of the problem and fix it there if you can, rather than try and suppress it's consequences with filters.
 
Good grief Adam. Not obvious?

Cones.

However, I've no idea where you need to put them. Polite suggestions only please.
 
How did you get on with this? I've not heard any more since the above. Does this mean success, or a pile of broken hifi outside your window? 8-]
 
Yes, I was thinking of this today. I had an electrician here who inter alia replaced a burnt out dimmer unit. I asked him about interference from dimmers affecting AV equipment. He seemed to think it could be a problem but then asked me (which made me think of Adam's set-up) whether the power and signal cables were run through the same conduit. He was very sniffy about this. :(
 
I can understand his reaction. But the point is that these devices are meant to *not* leak RF and the RFI rules require them to not do it.

Of course, in reality many devices will simply have been made disregarding this and they just stuck a 'CE' mark on it for show. However Adam's *other* speaker doesn't get the problem. And dimmers that cause problems can 'accidentially' get broken and replaced. :)
 


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