Ferrite Rod Core

ferrite rods, bars, slugs, plates and tubes are primarily used as magnetic cores in radio antennas, chokes, inductors and filters. in radio antennas, ferrite rods are useful from vlf spectrum to vhf spectrum. the advantages are small size, high q and compactness. ferrite rods and bars are available in standard lengths up to 12" long. these rods are available from 0.25" to 1" in diameter. they are available in materials from permeability of 7.5ui to 10, 000ui in both nickel zinc (nizn) and manganese zinc (mnzn) compositions. effective permeability coil placements and the length of windings on the rods, bars, plates and tubes affect the effective permeability of these devices. the corrected permeability for variation in coil length versus rod length is: where u' = corrected u ue = effective permeability from the chart lr = rod length in cm or inches lc = length of coil windings in cm or inches