Alan Peake wrote:

Steve, the usual reason for the apparent low Q is that it is not being
measured at the frequency that will give highest Q. Try fewer turns and
higher frequencies as a first attempt. I've measured many cores this
way. If you like, I can email you an XL spreadsheet with the all the
cores I've measured so far. Switchmode cores seems to have
permeabilities quite a bit higher than 600.
Alan
VK2ADB

Alan, are the ferrite toroids used to filter the output of pc power
supplies or the ac input of microwave ovens useful for other applications?

Or is the ferrite material lossy like the small ferrite beads used for emi
reduction on wires?

Regards,

Mike Monett