Cable TV floating at 40-50V above ground - how to fix?
Originally found by Time Warner cable technician fixing our broadband cable modem flapping issue. He disconnected our cable TV cable coming out from our house and measured about 40 volts between the connector on that cable to the ground on the splitter outside the house where their incoming cable was attached. The external splitter is grounded with a short 3ft cable and measured as low impedance connection to the nearby main residence ground rod. So the problem is not with the incoming Time Warner connection or the splitter ground.
I was able to narrow this down and measure 40-50 volts between an AC ground point and the RF connector directly on the TV (both ground and signal points) with nothing else plugged into the TV and with the TV plugged directly into a wall socket. So apparently this is not a ground loop. Also get 40-50 volts on the cable TV cable connector going directly to the TV decoder box, so that seems to rule out a TV appliance issue. I switched the TV to a different electric circuit using an extension cord with the same result. So probably not a specific electrical circuit issue.
Checked the electrical panel and all the hot, neutral, and ground connections are tight. I have a SureTest meter and none of the measurements, including the impedance of hot, neutral or ground appear to be of concern.
What next? It appears that the RF connectors on two appliances are 'floating' at 40+ volts, yet I can't find any obvious issues. I have an electrician coming out but they will not be here until Monday.
Any other suggestions or items to check? Could this be an external issue with the incoming electrical supply that would require the power company to check? Thanks.
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