I'm sure that we have all suffered from some kind of electrical noise interference during our time as Radio Amateurs,I know I have.

As some will know I keep a marine aquarium and like many fish keepers the fish grow and so the tank has to grow with them. It came to upgrade time and I had to buy a new aquarium and with that a new LED light Unit. I went on to ebay and bought a light that I knew came with good reviews and were a good price too, what I forgot was the friends that had used them in the past were not Amateur radio enthusiasts, I plugged it in DAMN ! The mains noise was ridiculous !!!!

Unfortunately I didn't get a screen shot when it was at its worst, the ones above were taken during testing and they had already been reduced by me making a basic RF choke, but you get the idea

I was experiencing +30db on top band, +20 on 80 meters, +10 on 40 meters and so on, OH NO !!!

So like we do, I got straight to work on GOOGLE (other search engines are available) and started to do some research and came across EMI filters that were available from around £15 Upwards for a 1/2 decent one, but then you get that thought in your head "will it work"?

Like we do I continued reading until the point the information was all conflicting and just confusing the life out of me, so I decided at this point to drop an email to Steve G1LMN, He promptly came to my rescue and came to my house armed with some test equipment and went to work making sure everything was as it should be, as luck had it I was heading in the right direction.

This is the curcuit we decided to go with

So I got the soldering Iron out and set to work to try and get this noise at the very least reduced, but as you can see from the Icom IC-7300 screen shots above it worked way beyond what I expected or Imagined..

The built circut :)

This is the circuit fitted into the LED light unit.