3622714

Information

• Patent Grant
• 3622714

• References
• Source

• Patent Number

  3,622,714

• Date Filed

  Not available

• Date Issued

  Tuesday, November 23, 1971
  53 years ago

• CPC

  • H04Q1/453 - in which m-out-of-n signalling frequencies are transmitted
  • H04B3/21 - using a set of bandfilters
  • H04M9/087 - using different frequency bands for transmitting and receiving paths ; using phase shifting arrangements

• US Classifications

  • 379 - Telephonic communications
  • 381 - Electrical audio signal processing systems and devices