Rf Interference being fed back into my bench power supply. Solutions?

[diydidi]

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.

 

[bruno2000]

Could be the RF is getting into the metering circuit of the PS.  Poor shielding?  Looked at it on a scope?
Best,
Bruno2000

 

[JohnRoberts]

LxC filter in PS lead.

JR

 

[culteousness1]

Is your bench supply switching-mode or linear? And I don't get your exact set up.
Does the meter circuit only go up while your Fluke stays at 9 V in parallel?

None the less, you should add some proper EMI protection to your RF transmitter's
power inlet.  These are available off-the-shelf in THT or SMT. Check Murata for example...

Best,
Carsten