Frequency-Modulated Magnetic-Tape Transient Recorder

A transient recorder having a frequency range of 0.02 to 1000 cycles per second with useful response up to 2000 cycles per second is discussed. The transient is recorded on a loop of magnetic tape and played back synchronously every 0.1 second on an oscilloscope screen. Thus, a steady image of the transient is obtained. Excellent signal-to-noise ratio (40 decibels) is obtained by the use of a 10-kilocycle carrier, which is frequency modulated. Each recording can be obliterated by simply pressing a button, with no material being consumed.