ronsch
Newbie level 4

I am a ham radio operator and am seeing EMI noise from a small Chinese 12VDC to 20VDC boost power supply in the 3Mhz to 30Mz range. The noise is on harmonics of approx 100Khz. The boost device is powered from a 12V battery (no input noise).
The EMI only appears when the boost circuit is wired to the radio (no emissions are visible when the boost is simply turned on). The small boost power supply only drives a 500ma load (but the load is a very sensitive preamplifier).
I am hoping that this is a simple problem for someone with the right knowledge. There is no input noise to the boost circuit, and I want to filter all noise on the output above 3Mhz. I have tried multiple loops on ferrite beads (type 31, 43, and F), without much success.
I would appreciate any advice on a simple LC circuit (with values), voltage regulators or any other simple solutions for a novice with minimal electronics theory background.
Thanks, Ron
The EMI only appears when the boost circuit is wired to the radio (no emissions are visible when the boost is simply turned on). The small boost power supply only drives a 500ma load (but the load is a very sensitive preamplifier).
I am hoping that this is a simple problem for someone with the right knowledge. There is no input noise to the boost circuit, and I want to filter all noise on the output above 3Mhz. I have tried multiple loops on ferrite beads (type 31, 43, and F), without much success.
I would appreciate any advice on a simple LC circuit (with values), voltage regulators or any other simple solutions for a novice with minimal electronics theory background.
Thanks, Ron