779508

Information

• Patent Grant
• 779508

• References
• Source

• Patent Number

  779,508

• Date Filed

  Not available

• Date Issued

  Tuesday, January 10, 1905
  120 years ago

• CPC

  • H04B1/582 - with automatic balancing
  • H04M3/2281 - Call monitoring

• US Classifications

  • 379 - Telephonic communications