Excess Spacing Loss with Alfenol-Core and Ferrite-Core Magnetic Tape Reproducing Heads
The head core material Alfenol (also called Vacodur) is long wearing, but produces an excess spacing loss, apparently dueto a nonmagnetic surface layer of about 0.4 µm that cannot be removed. Ferrite cores sometimes have gap erosion that also causes excess spacing. Because of this, heads with these core materials are not suitable for fundamental measurements. For ordinary sound recording purposes the excess spacing loss is easily compensated when the reproducer response is adjusted by playing a calibration tape.
This paper costs $33 for non-members and is temporarily free for AES members.