3825686

Information

• Patent Grant
• 3825686

• References
• Source

• Patent Number

  3,825,686

• Date Filed

  Not available

• Date Issued

  Tuesday, July 23, 1974
  50 years ago

• CPC

  • H04R21/021 - with granular resistance material
  • H04M1/03 - Constructional features of telephone transmitters or receivers

• US Classifications

  • 379 - Telephonic communications