Fair-rite publishes spreadsheets of the complex permeability characteristic of many of the ferrite mixes. This note is about #61 mix.
I have published various tools and articles based on the undated pre 2021 published data, and measurement results reconciled quite well with that data, taking into account the tolerance on the products.
I have added the #61 data I downloaded recently (unfortunately the files do not contain a date), and included the data in Ferrite permeability interpolations as shown in the above screen shot.
Above is a comparison of the two datasheet csv files.