Mains Filter

 

This started out as a way to try and stop my Broadband being knocked out when on HF but has also cut the noise level on the HF bands.

Like most things it all got very complicated etc until I found a blog post from M0NWK https://www.m0nwk.co.uk/mains-electricity-filter-for-emc-noise-reduction/

The construction is simple and straightforward.

Parts list

Fair-Rite type 31 ferrite core. I got mine on Ebay https://www.ebay.co.uk/itm/181209693756

Mains Cable. I used 1mm standard flex.

Box. Got mine from Screwfix

https://www.screwfix.com/p/british-general-ip55-weatherproof-outdoor-enclosure-180-x-110-x-135mm/96153

Construction was easy, I wound 6 turns around the ferrite. This is the recommendation og GM3SEK on his very useful web site http://www.ifwtech.co.uk/g3sek/in-prac/#big31  I used a couple of cable ties to hold it together.

 

The results so far are encouraging. I can now run 50w of FT8 on 17 and 10m without knocking out my G.Fast Broadband. Noise levels on the lower HF bands seem lower but nothing spectacular.

Completed. The 4 way block had been left in the sun!