So, regarding the philips dimmable dual ballasts that are churning out RF a= nd killing radio 4 FM on a radio 1.5 metres away.
I sent a note about this to BLTdirect who passed it on to philips. A reply = from BLTdirect included a PDF about installing philips ballasts, which stat= es that it is assumed that the ballast and wiring is inside a type 1 enclos= ure, which apparently means an earthed metal box.
I have tried ferrite cores on the wiring from the ballast which made little= difference. A large ferrite with the radio mains cable looped through it s= everal times makes the radio just about OK, but that is not solving the pro= blem at source.
The interference is not quite as bad on other radio stations so there must = be a peak around 92MHz. I think most of the interference is from the ballast itself.
The other thing that seems a bit weird but not surprising since the whole t= hing is an RF transmitter. If I connected a short length of wire to the met= al ballast body and held it straight and touched the other stripped end the= n the effect of my body virtually removed all the interference. Trouble is = I cannot stand there and hold it. I wonder it some capacitive circuit could= simulate this.=20
What a flippin' pain !
Anyway, it looks like the whole thing is going to have to go in an earthed = box. Anyone got any second hand 4 foot empty fluorescent luminaires, or know whe= re I can get them ? Otherwise I will have to buy cheapo lights and replace = the guts. I would probably use the existing connector for one tube and conn= ect the other one on short flying leads to push-on end caps. I have an old 5 foot that could be cut down but it has plastic end caps whi= ch would probably let the RF out, so that may be no good.
Wish I had got the osram !
Simon.