• Year
  • 1954–1956
  • Category
  • Audio Amplifier or -mixer
  • Radiomuseum.org ID
  • 286192
    • alternative name: National Toy Co.
    • Brand: Thrillbox

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

 Technical Specifications

  • Number of Tubes
  • 4
  • Main principle
  • Audio-Amplification
  • Power type and voltage
  • Alternating Current supply (AC) / 60 Hz, 117V = 110 -120 Volt
  • Loudspeaker
  • - This model requires external speaker(s).
  • Power out
  • 20 W (25 W max.)
  • Material
  • Metal case
  • from Radiomuseum.org
  • Model: Horizon 20 - National Company; Cambridge &
  • Shape
  • Tablemodel, with any shape - general.
  • Dimensions (WHD)
  • 14.5 x 4 x 11 inch / 368 x 102 x 279 mm
  • Notes
  • The National Horizon 20 is a 20 watt mono amplifier. It utilized National's Unity Coupled circuitry with push-pull 6L6G tubes. The amplifier lack any controls on the front, having a screwdriver type adjustment on the rear for gain and hum balance. It has inputs for TV, Phono, Tuner and Tape Playback, and will drive either an 8- or 16-ohm speaker.

    Frequency response is rated at +/- 0.1 db from 20 cps to 20,000 cps and +/- 1.0 db from 10 cps to 100 kc. Harmonic distortion is rated at 0.3% at 20 watts and 0.6% at 25 watts. Intermodulation distortion is 1% at 20 watts, and sensitivity is 1.6 volts at 20 watts output.

    The Horizon 20 was updated in 1956 to the Horizon 20A.

  • Net weight (2.2 lb = 1 kg)
  • 32 lb (32 lb 0 oz) / 14.528 kg
  • Price in first year of sale
  • 84.95 USD
  • Author
  • Model page created by Wayne Childress. See "Data change" for further contributors.

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