• Country
• Germany

• Manufacturer / Brand
• Sennheiser Electronic (Labor W); Wennebostel

• Year
• 1998 ?

• Category
• Loudspeaker, headphone or earphone

• Radiomuseum.org ID
• 358989

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

• Number of Transistors
• Semiconductors present.

• Semiconductors

• Main principle
• Audio-Amplification

• Power type and voltage
• Batteries / addl. power jack / NiH Ba151 / 12 Volt

• Loudspeaker
• - For headphones or amp.

• Material
• Plastics (no bakelite or catalin)

• from Radiomuseum.org
• Model: Kopfhörer Infraport RI 250, TI 250 - Sennheiser Electronic Labor W;

• Shape
• Miscellaneous shapes - described under notes.

• Notes

• Infrarot-Kopfhörer RI 250, FM Mono, Trägerfrequenz 2,3 MHz, Frequenzumfang 18 - 18000 Hz, Störabstand typ. 70 dB. Betriebszeit mit 1 Akku BA151 ca. 6 h. Der Akku BA151 kann im Sendeteil TI 250 aufgeladen werden.

  Infrared headphones RI 250, FM mono, carrier frequency 2,3 MHz.
  Frequency response 18-18 000 Hz, S/N typical 70 dB.

  Matching transmitter: TI 250

  Made in Ireland.

• Net weight (2.2 lb = 1 kg)
• 0.045 kg / 0 lb 1.6 oz (0.099 lb)

• Mentioned in
• -- Original-techn. papers.

• Author
• Model page created by Sándor Selyem-Tóth. See "Data change" for further contributors.

• Other Models

• Here you find 296 models, 281 with images and 136 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Sennheiser Electronic (Labor W); Wennebostel