Radio Reception with Signal Splitter

[dave_neal_59]

I built the signal splitter from Plate to Plate (schematic here: http://www.geocities.com/SunsetStrip/Studio/2987/split.gif).   It appears to work as it separates the ground and reduces the hum, however, I am getting outrageos radio reception with this thing.  I've tried an RC  low pass filter on the input side with no luck.  Any suggestions would be appreciated.