Monday, 28 January 2013

Mains Filter - Good Housekeeping ?

After reading an article in Radcoms 'In Practice' by GM3SEK sometime ago (May 2009) making reference to a filtered mains supply. This is based on a Belling Lee mains filter which filters line, neutral and earth. It is capable of passing 16 amps so well up to supplying the whole shack including computer.
Pictured is the unit mounted in a plastic box with plastic cable glands as strain relief. This unit then feed a strip of six sockets to supply the shack bench. obviously the lid must go on as there are exposed terminals with mains power.

The theory is that this unit should help prevent any RF currents going back into the house mains wiring possibly causing RFI issues. Another option is winding the mains cable on a stack of large ferrite cores.

GM3SEK's website


  1. Good morning Ian, very nice unit and I was wondering if you had any troubles with RFI getting into your AC in the past? I have ferrites on all my in and out cable going into my PC's as I did have trouble with RF getting into my mouse cord and some very minor monitor issues.

  2. Hi Mike, Thanks for comments.
    Never really had too much trouble in shack but I tend to run QRP powers.Though do suffer a little with received noise on HF bands.
    Ferrites on PC cables are a good idea, I do the same here.

    73 Ian