PURPOSE: To demonstrate harmonic distortion in an audiotape.

DESCRIPTION: Set up to record the wave generator square wave on tape. By switching the monitor on the tape deck to "SOURCE" you see the square wave after it passes the input and output preamps in the tape recorder. By switching the monitor to "TAPE" you see the square wave after it has been recorded and played back. The sound of either wave is heard using the power amplifier and loudspeakers. Changes of phase of the various harmonics during the recording and playback process results in disto rtion, or changing of the final wave shape. By expanding the horizontal (time) and vertical (voltage) scales on the oscilloscope, you can view the (approximately) 100 kilohertz "bias" voltage that is applied to the incoming wave before it is recorded.


REFERENCES: (PIRA unavailable.)

EQUIPMENT: Wave generator, Teac A2300S reel-to-reel tape recorder, audio cart system with amplifier and speakers as photographed, and oscilloscope on scope/TV cart.

SETUP TIME: 10 min.

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