Mains Filter

Here is my mains filter i made to help reduce RFI in the shack. I used Ian, GM3SEK's design. More info on his website here

For advice on building I used another Ian (G0CNN)'s you tube video here

Here is my effort:

First twist the cable cores

Use about 2m of heavy duty mains cable. Tape one end and hold it in a vice then slowly turn the other end with a cordless drill until it looks like above

Stick the two higher freq ferrites together

I used tape and tie wraps. Don't be tempted to tie wrap inside as you need the space in there for your cable

Wrap your wire through ferrites

Start with the snap on (7 turns - or 7 passes through the middle) then 3 passes through the smaller ferrites

Crimp on spade connectors and connect the additional mains filter

Pay attention to the orientation of this. LINE=Mains input, LOAD=Mains to your equipment

The earth lead spade has to hold both earths (so you will need a large enough crimp to get both wires in and leave enough length on your earth core to reach) which are earthed at the case of the filter

Place in a suitable box

I used hot glue to stick everything down

Place near to the incoming mains socket and power everything in your shack from it

You may need to experiment with this to find the best place as your mains lead can act as an antenna