The Sony Trinitron Monitor probably has a standby switcher supply.
It might even have an instant on feature (keeps the CRT filament on all the time).
I never understood for sure if you actually unplugged the Sony, and then checked the interference.
Off is not Off, it is standby, Right?
It might even have an instant on feature (keeps the CRT filament on all the time).
I never understood for sure if you actually unplugged the Sony, and then checked the interference.
Off is not Off, it is standby, Right?
Mains power outlets in the same room, are often parallel fed.
In that case, conducted emissions will go from one outlet to the other.
In that case, conducted emissions will go from one outlet to the other.
Post #14 said the monitor has been unplugged for a long time. My guess is this other outlet has a floating or bad ground. There’s definitely a capacitance issue if getting your hand near the tubes makes it quite down.
Monitor still connected to a computer that is plugged into the wall and possibly powered? If so try unplugging the monitor from the computer.
Bad outlet ground is another very likely cause.
Bad outlet ground is another very likely cause.
As said earlier a CRT line scan puts out a significant amount of radiation. So much so that in the UK they employed TV detector vans to check if those using a TV had paid their reception licence. These vans picked up the line scan frequency (15,625 Hz) and just by driving down a street could tell which room in a house the TV was operating.
An externally hosted image should be here but it was not working when we last tested it.