Magnetic Reference Lab 31J429

These tapes contain a series of recorded sine-wave signals for general-purpose use for standardizing azimuth, equalization, and sensitivity (usually called "gain" or "level") of open-reel analog audio magnetic tape reproducers.  They are not intended for testing tape reproducer speed, flutter, distortion, or track placement.

The signals on these tapes can be monitored with a voltmeter—either the program level meter in the tape reproducer or an external voltmeter.  Useful auxiliary test equipment includes a loudspeaker or headphones to hear the voice announcements of frequencies and levels, an oscilloscope to observe waveforms, and a level recorder in order to provide a graph of the frequency response.

Specifications:

• Tape Width: 1/2" (12.5 mm)
• Playing Time: 8 minutes
• Tape Speed: 15"/s (380 mm/s)
• Equalization Standard: IEC (IEC1)
• Fringing Compensated for narrow-track systems
• Level of Frequency Response Section: 0 dB
• Catalog Number for Reference Fluxivity (355 nWb/M): 31J429