Got a call from a guy saying he got a shock off a TV aerial lead. I went round and found that the exposed metal on the TV was sitting at 56 - 60 volts. Tried the other TV and it?s ok. I know it?s a fault on the TV but has anyone else ever seen this? The coax plugs into a three way splitter 1 from the aerial, 1 to the dodgy TV and 1 to the good TV. When all plugged together, 0 volts. So I think the good TV is holding the screen of the coax at 0 volts.
Yes! it's possible that the aerial socket might have been replaced at one time, and a non isolated socket has been fitted. Or the faulty TV has at one time been subjected to water ingress running down the co-ax, which over time can short out the isolating capacitors in the socket.
When I lived with the ex wife, I used to get a shock off the NTL set top box lead that went to the tv. Not a big shock, but enough to make your arm tingle a bit.
Paul, it's not uncommon. I've had the same - I think it was my previous set, a CRT Pannie TV and VCR. I can't remeber what the situation was exactly, only that I was realigning the aerial in t'loft and got a tingle from the cable (no amplifier used). Everything worked otherwise as expected. Worth contacting the TV manufacturer for their opinions?
Yes, some older televisions were double insulated so there was no requirement to earth them. But from the OP the chassis is metal so it should have a CPC. Have you checked the earthing arrangements in the property? perhaps no earth in place?? That would make more sense to have 50v+ on the chassis.
Thanks for the backing there Handy. I knew they never had an earth. Was something to do with the high voltage produced inside the sets. You certainly wouldn't have wanted tens of thousands of volts going through any earthing system of any property ( a time before we all had rcd's etc fitted)
The TV is Class 2, ie no earth. It's still in warrenty so Mr Client has taken it back to the shop. Thanks for the comments.
Yes agree HA..have felt tingles before on aerial connections..it makes you wonder if the PD is dragged from the central core onto the coax braid, and if this is the case would it be beneficial to drag the braid down to earth..
Dunno about the PD being dragged to the coax braid, JP, but I wish it wouldn't. PS, my dad is a professional entertainer and on his set up, he doesn't connect the earths to every bit of equipment he has. Apparently it can cause an "earth loop" which causes hum through the speakers. I've tried telling him to sing instead of humming, but he pays no attention to me.
I'm not too sure, but with some amplifying stuff, an earth can act as a sort of aerial, which causes hum. In other cases(as in old machines), it was essential to connect to earth to STOP the hum. Strange stuff, sound. Mr. HandyAndy - Really
Well Handy, my dad has an echo unit, microphones, guitar and keyboards all plugged into one amplifier. Apparently it does work ( I have seen and heard the results for myself) Perhaps some electrician or nuclear scientist, would care to elucidate further on why this should be??