oe7drt-website/content/equipment/radio-stuff/accessories/homebrew-common-mode-choke/index.md

821 B

title summary coverCaption date lastmod showBreadcrumbs showReadingTime showWordCount
Homebrew common mode choke A simple and quite tiny common mode choke that I built for my portable operations. My selfmade common mode choke placed into a neat plastic case with BNC connectors. 2023-10-26T13:36:26+02:00 2025-03-09T11:08:33+0000 true false false

So this is basically a 140-43 toroid with 9 turns of RG174 connected to BNC connectors.

It works very well and I have made two measurements:

{{< figure src="logmag_through.png" caption="The maximum loss is on 10m around 0.2dB" >}}

{{< figure src="logmag_outer.png" caption="It attenuates common mode current with more than 20dB" >}}

Another picture with open case:

{{< figure src="choke-inside.jpg" caption="A look inside the "plastic"" >}}