As some of you mite remember some time last year I bought a 10mA RCD socket to protect my test/workbench sockets when it arrived I fitted a beefy length of flex to it with a plug on and set it up in position great so far. One of the items plugged in is a frequency counter which I always have on when I'm using my ham radio transmitter it all worked well when I was on 14 Megs and on 7 Megs however when I was on 3.7 Megs the RCD would trip. Disaster! After a bit of head scratching and un lady like language I fitted a mains filter between the RCD socket and the bench socket boards this fixed the problem but weirdly now if I don't have the counter on (I forgot it by chance one day) it now trips whatever band I'm on but all is ok with the counter on. The reason I'm sharing this is because if any of you get trouble with electronic trips then a mains filter mite help not easy to add in a DB I know but thought ide share anyway
I could snipe a bit and say typical sparks to focus on one detail and miss the bigger picture. Yes the plug on in the video is old - but fact he has made a test socket 2 tails with plugs on it so he can switch from with mains filtering to without is a far greater potential hazard, if you worry about such things. - realise that the pins of the one that is not plugged in are still live !!
Wiring a switch across the filter would have been a safer demonstration.
However, putting that to one side the video is also a very good demo of why filters that do not choke the earth as well as L and N are sometimes quite ineffective against certain types of mains borne interference, and just how good a well placed chunk of ferrite can be. I'd like to hope that after the demo he has taken that test lead apart or at least kept it out of circulation.
I could snipe a bit and say typical sparks to focus on one detail and miss the bigger picture. Yes the plug on in the video is old - but fact he has made a test socket 2 tails with plugs on it so he can switch from with mains filtering to without is a far greater potential hazard, if you worry about such things. - realise that the pins of the one that is not plugged in are still live !!
Wiring a switch across the filter would have been a safer demonstration.
However, putting that to one side the video is also a very good demo of why filters that do not choke the earth as well as L and N are sometimes quite ineffective against certain types of mains borne interference, and just how good a well placed chunk of ferrite can be. I'd like to hope that after the demo he has taken that test lead apart or at least kept it out of circulation.
