Rf Interference feeding back into my bench power supplies

Hi.
I have some chinese digital readout variable power supplies. Recently I built a little RF transmitter. It operates at around 100Mhz. When I set my power supply for 9V output, and power the little transmitter from it, the digital Led readout goes up to 13V, and the current Led display to 60mA.
If I connect my fluke to the power supply output, it still shows 9V.
So the transmitter is feeding RFI back into my power supply. How do I fix this??
I know it has something to do with chokes, but I don't know much about these.

Put a good quality 100nf cap across the supply terminals, try it on the outside of the psu first, if it works you can make it a permanant internal fixture.
2 chokes or a differential choke might work but they are much bigger.