• Country
• Japan

• Manufacturer / Brand
• Sony Corporation; Tokyo

• Year
• 1977–1979

• Category
• Microphone or Pick-up element

• Radiomuseum.org ID
• 121430

Click on the schematic thumbnail to request the schematic as a free document.

• Wave bands
• - without

• Power type and voltage
• No Power needed

• Loudspeaker
• - For headphones or amp.

• Material
• Various materials

• from Radiomuseum.org
• Model: Electret condenser microphone ECM-990 F - Sony Corporation; Tokyo

• Shape
• Miscellaneous shapes - described under notes.

• Notes
• Hand held one point stereo electred condenser microphone, 40 - 16.000 Hz, 2× 6,3 mm plug, 200 ohm out.
  An electret is a stable dielectric material with a permanently-embedded static electric charge. An electret microphone is a type of condenser microphone, which eliminates the need for a power supply by using a permanently-charged material. Electret materials have been known since the 1920s, and were proposed as condenser microphone elements several times, but were considered impractical until the foil electret type was invented at Bell laboratories in 1962 by Gerhard Sessler and Jim West, using a thin metallized Teflon foil.

• Mentioned in
• Sony IFA Katalog 1979

• Author
• Model page created by a member from A. See "Data change" for further contributors.

• Other Models

• Here you find 4061 models, 3918 with images and 974 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Sony Corporation; Tokyo