2733299

Information

• Patent Grant
• 2733299

• References
• Source

• Patent Number

  2,733,299

• Date Filed

  Not available

• Date Issued

  Tuesday, January 31, 1956
  68 years ago

• CPC

  • H04Q1/4535 - with an additional signal transmitted for voice protection

• US Classifications

  • 340 - Communications: electrical
  • 375 - Pulse or digital communications