Re: How do you test a toroid?

Donald Kelly

Hi Steve,


I assume you know the ultimate inductance of the coil you are winding. A handy tool to have is a L/C meter.

Not all toroids are alike and it is always a good idea to measure. My guess is most of the guys have one of these.


This  meter evolved from a homebrew project by Bill Carver, W7AAZ. A digital readout was added later for easier use. The original project is classic in its simplicity.

It is also included in “Experimental Methods in RF Design” in the test gear chapter.



My version is used all the time. You can see the ugly style board is very simple. The trick is in the calibration steps and having a precision calibrating capacitor.


Test gear is fun to build and a great way to get started in scratch projects.






From: 4sqrp@... [mailto:4sqrp@...] On Behalf Of w1sfr
Sent: Tuesday, March 26, 2013 11:18 AM
To: 4sqrp@...
Subject: [4sqrp] How do you test a toroid?



The transforming toroids are pretty tricky to wind. Is there any way to test them to find out if you've done it correctly?


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