I think farmers are probably quite big gamblers! Every harvest is a gamble.

I'm very happy to agree that I'm no expert on the regs (these days I'm mainly a farmer) - that's why I asked the question! I simply wanted to understand whether the BMU built to Class II regs, would be compatible with acting as the mains feed for equipment built to Class I regs. As I'd mentioned, mo...

OK thanks - I'd hoped that was the correct interpretation of your message.

Do you care to share any info on the BMU ground connection question at the end of my post?

Cheers. Bill

Sorry, I hope I'm not now being classed as a 'forum egotist' for simply sharing my experience and trying to explore an interesting subject - well I find it interesting anyway! The majority of my current kit is built to Class I and the reason for my interest in earthing issues. I'm considering the 'c...

OK Thanks.

Cheers. Bill

Won't the vibration of the primary winding within its field create some sort of 'back emf' - I suppose you feel that this effect will be very small? Might the vibration of the transformer cause a vibrating field around the transformer itself, and this cause induced currents in circuits close by? I'm...

Thanks for the detailed response. If possible, perhaps we could put my knowledge to one side (I think I do basically understand - many years ago BSc in Electronics at Southampton, plus a number of years working on fast jet aircraft audio systems, plus other relevant jobs, gave me a fair understandin...

So, I think that you're saying that there is NO negative effect, apart from the directly audible hum, from a buzzing transformer in an amplifier as a result of dc on the mains - are you convinced there are no other resultant knock-on effects? My limited experience is that the DC Blocker I'm using no...

That's not what has happened in my experience - that's why I posted!

Cheers. Bill

I recently picked up a second hand DC Blocker for just the £8 cost of postage, it's an old sjostrom audio board (see sjostromaudio.com DCT01) fitted in a plastic box with a couple of 13A sockets on the outside and a fairly thin captive lead feeding it from the mains. I simply connected it in the sup...