|Material Mix No.||Reference Permeability||Powder Type||Temp Coef of Perm (+ppm/C°)||Density gm/cm3||Max Frequency (MHz)||Relative Cost||Color Code Toroid||Product Group|
‐2, ‐4, ‐6 & ‐7 Materials: These are the most popular carbonyl iron mixes. They will provide High Q up to 40 MHz and the most popular for amateur radio and variety of other communication applications. They are also useful for moderate band transformers in the 200 to 400 MHz frequency range
‐1, ‐3, ‐8 & ‐15 Materials: These materials are annealed carbonyl irons providing the highest carbonyl permeability. They are useful for high Q applications below 1 MHz and will provide the broadest band transformers covering a typical range from 50 to 500 MHz.
‐10 & ‐17 Materials: These materials are the highest frequency carbonyl irons. They will provide high Q up to 150 MHz and are a popular material for cable television applications. They will produce moderate band transformers covering 400 to 700 MHz.
‐0 Material: This is a non‐magnetic material. It provides a solid winding form for winding air coils. It has excellent temperature stability and will provide high Q up to the highest frequencies. It is also useful for moderate band transformer applications covering a typical range from 600 MHz to 1 GHz.