2319339

Information

• Patent Grant
• 2319339

• References
• Source

• Patent Number

  2,319,339

• Date Filed

  Not available

• Date Issued

  Tuesday, May 18, 1943
  81 years ago

• CPC

  • H04Q1/4535 - with an additional signal transmitted for voice protection
  • H04Q1/453 - in which m-out-of-n signalling frequencies are transmitted

• US Classifications

  • 340 - Communications: electrical
  • 379 - Telephonic communications