The efficient use of recording media in a magnetic recorder is the goal of advanced development efforts in longitudinal digital recording at RCA. The rotating head transverse scan (quadraplex) equipments utilized in broadcast television and wideband (4-15 mHz) instrumentation applications provide a prime example of the efficiency possible. The transverse scan equipments conforming to ASA standard C98.6 (1965) half track tape format record a 5.0 mil track with a 2.8 mil guardband which yields 128 tracks per inch of tape. When operating at 25 KBPI in-track packing density, these equipments obtain an area packing density of 3.2x106 bits per square inch. IRIG standard multi-track fixed head equipments conversely yield an area packing density of .07x106 bits per square inch when operating at the same 25 KBPI but only 28 tracks per inch.
J. S. Griffin, J. S. Griffin,
"Ultra High Data Rate Digital Recording", Proc. SPIE 0036, Military Airborne Video Recording: Requirements, Utilization, and Technology, (1 October 1973); doi: 10.1117/12.953701; https://doi.org/10.1117/12.953701