noise

have av reciever picking up noise from low voltage txs ,dimmers or sited remotely in other room quiet some distance away gets worse as you reduce light level ,any help most apreciated.

cheers conor

 

When lighting control and av equipment are installed in close proximity, there will always be some compatibility issues. The obvious recommendations are to try and maintain the maximum physical separation of the two systems - that means cabling as well as other hardware.
Of course, av cabling should all be shielded, but shields can't always keep out the noise. It is useful to run any av cabling in (earthed) metal trays or in metal conduit, or at least maintain an earthed barrier between the av cabling and any mains (lighting) wiring.
If all else fails, ferrites are your friend.
Clip-on ferrite cores are very useful in choking off 'common-mode' currents induced in the av cabling. They are easy to use; just clip them over the shielded cables. Multiple cables can be passed through the same ferrite core for the same effect. Clip on ferrites cores generally have high permeability, and can be useful down to audio frequencies. In one instance I have had to resort to high permeability ferrite toriodal cores to choke off audible noise, but that was extreme (alternator noise in a vehicle being induced into audio wiring).

I've found most problems like this can be reduced to the point of not being annoying with the above methods.

 

I'd suggest a first try is to change transformers, particularly to a better quality one. Have had similar noise issues with chinese ones.

Not totally related but I got the fright of my life when I used some cheap chinese txfmrers and I dimmed to a low level, after about an hour the lights started to flicker and from an adjacent room it look like the room was on fire. Much relieved when it was simply the lights flickering. I changed the txfrmrs and no problems since.

 

thanks
will try fitting ferrite filters first as there are aprox 60 electronic tx in room ,they are "G.e.t "from a schnider owned company .