Ok I'm an idiot. I remembered I had a NVR that I ordered to play around with. It had a two amp switching power supply that is obviously not big enough but I unplugged one camera and plugged it into the 4 way splitter and problem appears to be gone. I was so obsessed with the idea that it was a ground loop problem that I thought only a transformer wall wart would solve the problem. Anyways I'm still curious about the safety and efficiency of the isolation transformer.

 

Thanks for the responses here. It may seem insignificant but it should restore faith in our fellow man that there are people who want to help other people without any obvious self serving interest.

I have been searching for a replacement power supply and it is absolutely appalling to read through the reviews and find how many people have received faulty supplies. Some like me found that replacement supplies caused electrical interference and other minor problems but it is frightening how many people have had the devices catch on fire, melt the cables or ruin their equipment. It is as if we have all become as consumers the quality control end of the small electronics industry. That is ok for many devices because the price has dropped so dramatically that each of us can carry around more computing power in our pocket than large companies had a few decades ago. Power supplies are the exception to the rule that it is more efficient to have customers return devices than implement through quality control because of safety. A laptop that catches on fire cannot be equated with on that simple does not function as intended.