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Sound recording system

  • US 4,141,344 A
  • Filed: 03/02/1978
  • Issued: 02/27/1979
  • Est. Priority Date: 03/02/1978
  • Status: Expired due to Term
First Claim
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1. In a recording system for a sound recorder having an input, the combination of:

  • a signal generator for generating an A.C. signal of predetermined amplitude within the frequency range below about 14 Hz.;

    means for combining additively with said A.C. signal an audio program signal falling substantially within a frequency range substantially above 14 Hz. and of substantially smaller amplitude than the maximum amplitude of said A.C. signal;

    and means for applying the additively combined audio program signal and A.C. signal to the sound recorder input.

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