Palomar and Amidon both sell materials from Fair-Rite. Fair-Rite's catalog
has curves showing 77 to be better than 43 up to 30 MHz. However, here at
Palomar we ran tests showing that 43 is better than 77 from 7 MHz up. The
tests included the .82" and the 2.4 inch toroids. So there is a question.
The Fair-Rite measurements were made long ago. Possibly the mixes have
changed. Who knows? Ed Hare at ARRL plans to make independent tests on a
number of toroids and beads. So before long we should know for sure. --
Jack, K6NY
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