3758728

Information

• Patent Grant
• 3758728

• References
• Source

• Patent Number

  3,758,728

• Date Filed

  Not available

• Date Issued

  Tuesday, September 11, 1973
  51 years ago

• CPC

  • H04B17/408 - using successive loop-backs

• US Classifications

  • 379 - Telephonic communications
  • 324 - Electricity: measuring and testing