Examining unknown toroid core.

10 for $5.65 0.87" OD doesn't sound bad BUT what are they and what can they be used for? The reviewers give good reviews but no one knows the material. First I download Mini Circuits mini ring program. Second I wind 40 turns on one of the cores. Third I measure the inductor I just wound. Fourth I insert the data in the program.

After entering the data I press the button at the upper right screen.  Done with that step. Now how to use the data obtained.

From unknown to usable. Back in the main program click copy AL from tool and click Copy Dimensions from Tool. The data is set enter desired inductance, in this case 121 uh and click the =>. The program tells you how long the wire needs to be and what the max size can be.

All that's left is to put a couple of turns for a primary and send a signal through the transformer formed to observe the frequency response. It looks very promising if it will work at the frequency range desired.

As my final test I did put 7 turns on a core and it checked good. It would be good to check frequency response.