913521

Information

• Patent Grant
• 913521

• References
• Source

• Patent Number

  913,521

• Date Filed

  Not available

• Date Issued

  Tuesday, February 23, 1909
  116 years ago

• CPC

  • H04J7/02 - in which the polarity of the amplitude is characteristic
  • H04L1/1664 - the supervisory signal being transmitted together with payload signals; piggybacking

• US Classifications

  • 370 - Multiplex communications
  • 340 - Communications: electrical
  • 379 - Telephonic communications