• Year
  • 1951/1952
  • Category
  • Amateur-Receiver (amateur bands, may include broadcast bands)
  • Radiomuseum.org ID
  • 49567
    • 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
  • 15
  • Main principle
  • Superhet with RF-stage; ZF/IF 455 kHz
  • Wave bands
  • Broadcast, Long Wave and more than two Short Wave bands.
  • Power type and voltage
  • (110-120; 220-240 V ?)
  • Loudspeaker
  • (- This model requires external speaker(s). ?)
  • Power out
  • 8 W (unknown quality)
  • Material
  • Metal case
  • from Radiomuseum.org
  • Model: HRO-50-1 - National Company; Cambridge &
  • Shape
  • Boatanchor (heavy military or commercial set >20 kg).
  • Dimensions (WHD)
  • 501 x 257 x 420 mm / 19.7 x 10.1 x 16.5 inch
  • Notes
  • (

    The National HRO-50 family are AC operated multi-band communications receivers. 

    Note that the original HRO-50 and the updated HRO-50-1 models are generic and not actual models offered for sale.  They are sold as the T table model or the rack mount model.

    Features include:

    • Bands: 0.05 - 30 MHz (9 coil sets 50-100 / 100-200 / 180-430 / 480-960 / 900-2050 kHz / 1.7-4 / 3.5-7.3 / 7-14.4 / 14-30 MHz),
    • Bandspread in HAM bands,
    • AM/CW/SSB (BFO),
    • First HRO model with internal power supply,
    • Headphone jack on front panel,
    • Optional external speaker HRO-50TS for table models or HRO-50RS for rack models,
    • Optional crystal calibrator unit XCU for original T/R models or XCU-50-2 for updated T1/R1 models,
    • Optional narrow band-FM adaptor NFM-50,
    • Optional 650S 6V-vibrator pack, and
    • Select-O-Ject notch filter SOJ-3.

    The family models are:

    Model Table/Rack Mount Tubes
    HRO-50T Table 17
    HRO-50R Rack Mount 17
    HRO-50T1 Table 15
    HRO-50R1 Rack Mount 15

    See also R460/UR version for US Coast Guard.

    ?)
  • Net weight (2.2 lb = 1 kg)
  • (94.714 lb (94 lb 11.4 oz) / 43.000 kg ?)
  • Price in first year of sale
  • (335.00 ?)  (USD ?)  
  • External source of data
  • Ernst Erb
  • Source of data
  • (will be deleted ?)
  • Circuit diagram reference
  • Rider's Perpetual, Volume 22, covering 1951
  • Mentioned in
  • (Communications Receivers ?)
  • Literature/Schematics (1)
  • (Photofact Folder, Howard W. SAMS ?) (Set 169, Folder 11, June 1952. ?)
  • Literature/Schematics (2)
  • (Shortwave Receivers - Past & Present (4th ed.) ?) (page 485. ?)

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