You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
31 lines
909 B
31 lines
909 B
---
|
|
title: Homebrew common mode choke
|
|
summary: |
|
|
A simple and quite tiny common mode choke that I built for my
|
|
portable operations.
|
|
coverCaption: My selfmade common mode choke placed into a neat plastic case
|
|
with BNC connectors.
|
|
date: 2023-10-26T13:36:26+02:00
|
|
lastmod: 2024-03-31T11:02:19+0000
|
|
|
|
showBreadcrumbs: true
|
|
showReadingTime: false
|
|
showWordCount: 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 recently.
|
|
|
|
{{< 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" >}}
|
|
|
|
I find this okay for now but I still wonder if this can be made any better
|
|
(maybe 30dB attenuation?). Would I benefit from even more attenuation?
|
|
|
|
I will probably find out on another day.
|
|
|