issue: Crt's in two arcade cabinets start waving when placed next to each other

[trick72]

Hi,
I have two arcade cabinets with CRT screens. I want to put them in my gameroom right next to each other. Sadly when I do this, the crt monitors start "waving" on the side where they are standing to each other. So the right cabinet is waving on the left side of the screen and the left cabinet has waves on the right side. When one of them is powered off, the picture doesn't wave anymore. So they are somehow interfering with each other.
I do remember from the arcades back in the eightees that such cabinets were always "in a line" right next to each other, and I don't remember them waving that way.
Any idea why this happens and what I can do about it? Some shielding? but how and where?
Thanks

[PL1]

the crt monitors start "waving" on the side where they are standing to each other. So the right cabinet is waving on the left side of the screen and the left cabinet has waves on the right side. When one of them is powered off, the picture doesn't wave anymore. So they are somehow interfering with each other.

That's electromagnetic interference (EMI) -- either from the monitor's magnetic fields or radio frequency (RF) signals.

You'll probably need some shielding material like thin sheet metal between the monitors.

Quick and dirty test -- hold a metal cookie sheet between the monitors and see if that fixes it.


Scott

[trick72]

Thanks for your reply.
Indeed holding a large oven baking plate between the cabinets reduces the waving a lot...
So I guess I need to find a way to put a metal "sheet" in between the cabs.. still wondering how they did it then in the arcades... but thanks for pointing it out.

[PL1]

So I guess I need to find a way to put a metal "sheet" in between the cabs..

Pull the monitor then screw a thin piece of sheet metal on the inside of each cab next to the monitor and tie it to frame ground (AC power input green wire) using a ring or spade terminal and length of wire.




Scott