This is how to eliminate the Common Mode Current, a real pain in the ass sometime !

What is needed:

• 2x Ferrite Toroid FT240/43 ( if you use 100watt only 1 toroid will be enough)
• RG316 (10 meters for use with 2 toroids, a bit less if you use just one)
• Waterproof box (this is perfect !)
• Nano VNA to check the result

I decided to use two toroids as my intention was to use it in DX Pedition, wehre I always use my 300watt Power Amplifier RM305 from RM Italy Avoid to use glue, could give trouble with if wet; you can strap the two toroid together with plastic ties; then I choose the RG316 as is a Teflon Coax Cable that has an excellent heat dissipation, and it is also very easy to twist on the toroid

Also, I double the cable to support until 500watt use !

The circuit is very simple, and photos speaks for themselves… after some test, I found the best result making 11 coils aroeund the toroids…. the attenuation was really excellent in each band :

• 10 Meters Attenuation of -36dB
• 15 Meters Attenuation of -42dB
• 20 Meters Attenuation of -55dB
• 40 Meters Attenuation of -52dB
• 80 Meters Attenuation of -56dB