Radio Frequency (RF) Iron Powders
General Material Properties
Material | Reference Permeability |
Powder Type | Temp Coef of Perm (+ppm/C°) |
Density gm/cm |
Max Frequency (MHz) |
Relative Cost | Color Code Toroid |
---|---|---|---|---|---|---|---|
-0 | 1 | Phenolic | N/A | N/A | N/A | 1.2 | Tan/Tan |
-1 | 20 | Carbonyl Iron | 280 | 6.4 | 10 | 3.6 | Blue/Clear |
-2 | 10 | Carbonyl Iron | 95 | 5 | 45 | 2.0 | Red/Clear |
-3 | 35 | Carbonyl Iron | 255 | 6.5 | 5.0 | 3.2 | Gray/Clear |
-5 | 5 | Carbonyl Iron | 280 | 5.0 | 10 | 2.1 | Green/Clear |
-6 | 8.5 | Carbonyl Iron | 35 | 5.0 | 55 | 5.1 | Yellow/Clear |
-7 | 9 | Carbonyl Iron | 30 | 5.0 | 50 | 3.8 | White/Clear |
-8 | 35 | Carbonyl Iron | 255 | 6.5 | 5.0 | 2.7 | Yellow/Red |
-10 | 6 | Carbonyl Iron | 150 | 4.9 | 83 | 5.6 | Black/Clear |
-15 | 25 | Carbonyl Iron | 190 | 6.4 | 7.0 | 3.2 | Red/White |
-17 | 4 | Carbonyl Iron | 50 | 4.8 | 170 | 3.7 | Blue/Yellow |
- ‐2, ‐5, ‐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.