Isolation transformer problems

[hillbilly]

Hey All

I have just got my first arcade cabinet together and it is a cocktail table. I have a isolation transformer in it but it is not shielded and is causing the screen to not display right. I have looked around locally and could not find a shielded iso. Is there a simple way to shield my existing iso?

[menace]

i've had iso's right beside the monitor with no problems--how do you know its that?  have you got any speakers close by?  What exactly is your screen doing?

[hillbilly]

I have determined it is my Iso because when I had the monitor on a table when I was setting up mame I had color problems on the side the Iso was on. when I had the monitor was horz the color problem was on the right, when I rotated the monitor to vert the color problem was still on the right. When I mounted it in my cocktail cab the Iso was below the monitor and I got a more distributed color problem. When I moved the Iso externally the problem goes away. So after all that I can say with a pretty high degree of certainty it is my Iso.

[Ken Layton]

I think Happ Controls sells shielded isolation transformers.

[ChadTower]

You can use a coffee can turned upside down as a good RF shield... just make sure to coat it with something nonconductive to be safe.

[hillbilly]

I bought my isolation transformer from happ i didn't know at the time about needing a shielded one or if one was available.
I can try using a can and placing it over the ISO any tips on what i should cover the can with though? will it need to be coated inside and out to make it safe?
will any metal box around the ISO work?