10 Pack Toroidal Ferrite Cores Suitable for FT-82-43 Ferrite Toroidal Core

I’ve used about half of these and they work great. Very versatile!

Item arrived exactly as expected. Worked great for my project.

I have been using these to build small end-fed antennas for portable, low-power use in the "spark plug" form factor. They work great. These are tiny and lightweight, with a useful protective coating to prevent chips in the ferrite material. The coating's texture also provides some useful friction that prevents the wire windings from sliding out of place while constructing on the transformer. For my usage with 5W output and around 50% duty cycle, 22 AWG wire is about the thinnest wire winding I like to use, and it works great here. For other radio modes you might be able to get away with something smaller, but winding the transformer will be more unwieldy. I think this is a great value for ten toroids that perform really well.