here is the chart for fair-rite torroids.
I use mainly the bottom 3, since the Al number is so high.
People laughed at my "hockey puck" inductor, but you know what, it was the easiest to wind, had the fewest turns which means high Q, and it was cheap! (free sample)
Let me know if anyohne is interested and I can try for some more samples.
The stuff is brittle. every time they send samples, half the lot come in broken!
maybe thats whay the ship so many!
Thats the Al number on the far-rite, (get it! far-rite ha ha)
the -- marks would be filled with 77.
the dims are self explanatorium.
cj