Just wondered which is the most efficient core material, where to source it, is there pre-built ferrite cores available anywhere, is anyone selling good cores etc etc.
Thanks.

I was keeping an eye on this thread, as I am struggling with this at the moment as well.

The goal is to use similar components and setup to achieve reproducable results if someone finds 'the holy grail'. Though on core material it does not seem there is a consensus yet...

Quote from gpssonar on November 11th, 2016, 11:52 AM

The core material must meet or exceed the required frequency you're going to be using without saturating the core material. It also needs to be able to raise the inductance into the range needed for the LC circuit.

I know of a member (Olhu) that is using a TDK N27 ferrite core (AL Value of 5400nh), and is cutting it to size to Stan's original 5 coil VIC dimensions.

What are the crucial specs to consider when looking for a ferrite core? (2000µ or lower?) Dimensions?
Also, where have members found ferrite material to work with?

Anyway, any feedback on this topic would be helpful!

Here they sell some U cores, 60x55x15 is good size

http://powermagnetics.co.uk/pace-components/ferrite-cores/u-cores

Only I need SM magic u core...

http://open-source-energy.org/?topic=170.msg3704#msg3704
http://www.cmi-ferrite.com/Materials/Datasheets/MnZn/MN67.pdf

~webmug

https://drive.google.com/file/d/0B2WHxX-dD1NhQTNHN2ZBY3dQZW8/view?usp=sharing

https://drive.google.com/file/d/0B2WHxX-dD1NhYVBGZFdaNUJqQ1k/view?usp=sharing

https://drive.google.com/file/d/0B2WHxX-dD1NhdG9Famo2UXhiek0/view?usp=sharing