31-08-2014, 10:15 AM
The BAG unit I have is already encapsulated in an earthed metal case - the problem is that the output is several hundred volts at ~110kHz. It's a reasonably clean sine wave at the usual brightness I use (about 25%), but as you increase the brightness, the frequency falls and progressively becomes more distorted. At max, it's 50kHz and it looks a bit more like a triangle wave. The HF switching noise looks to be reasonably well attenuated on the 'scope (I don't have a spectrum analyser).
It's no wonder that radios are bothered by this, and I'm not sure how much help screening/filtering would be - not least because the whole tube is a radiating antenna... Still, the extra light is invaluable for close-up stuff and not really needed for lining up a set, so it works OK in practice - but it is a shame I can't replace all the lights down here with HF ballasts.
It's no wonder that radios are bothered by this, and I'm not sure how much help screening/filtering would be - not least because the whole tube is a radiating antenna... Still, the extra light is invaluable for close-up stuff and not really needed for lining up a set, so it works OK in practice - but it is a shame I can't replace all the lights down here with HF ballasts.
