• Year
  • 1939–1953 ?
  • Category
  • Service- or Lab Equipment
  • Radiomuseum.org ID
  • 332238
    • alternative name: GenRad

 Technical Specifications

  • Number of Tubes
  • 3
  • Wave bands
  • - without
  • Power type and voltage
  • Alternating Current supply (AC) / 115 Volt
  • Loudspeaker
  • - - No sound reproduction output.
  • Material
  • Metal case, TUBES VISIBLE
  • from Radiomuseum.org
  • Model: Strobotac 631-B - General Radio Company;
  • Shape
  • Tablemodel without push buttons, Mantel/Midget/Compact up to 14
  • Dimensions (WHD)
  • 7.5 x 8.75 x 9.875 inch / 191 x 222 x 251 mm
  • Notes
  • The Strobotac Type 631-B supersedes the Type 631-A. The Type 631-B was first listed in the General Radio Catalog K1 (1939), while the Type 631-A was no longer listed.

    Regarding the Strobotac's Strobotron Cold-Cathode Neon Flash Tube, the Type 631-P1 is listed for all variants of the Strobotac Type 631 series.

    Regarding the Strobotac's Full-Wave Rectifier and Power-Amplifier Twin Triode, the General Radio Catalog K1 (1942) lists 6X5 (Full-Wave Rectifier) and 6N7 (Power-Amplifier Twin Triode). Starting with Catalog K2 (1942) and ending with Catalog K5 (Late-1945), the the Rectifier and Triode are listed as Type 6X5-G and 6N7-G. From General Radio Catalog L (1948) through Catalog M (1951), the Rectifier and Triode are listed as 6X5-GT/G and 6N7-GT/G.

    Regarding the Power Consumption of the Strobotac, the Type 631-B is listed at 25 Watts in General Radio Catalog K1 (1939) through Catalog K5 (Late-1945). The Power Consumption is then revised to 35 Watts in Catalog L (1948) and then to 35 Watts Maximum in Catalog M (1951).

    Regarding the Strobotac's Weight, Catalog K1 (1939) listed the Type 631-B at 10 lbs, while Catalog K2 (1942) through Catalog K5 (Late-1945) listed it at 8.75 lbs, and Catalog L (1948) through Catalog M (1951) listed it at 9.5 lbs. As a comparison, the Type 631-A was listed at 12 lbs in Catalog J (1936).

    Regarding the Strobotac's Dimensions, General Radio Catalog K1 (1939) through Catalog M (1951) lists the Type 631-B to measure as follows: W 7.5" x L 8.75" x H 9.875".

    Regarding the Strobotac's Power Supply, Catalog K1 (1939) lists the requirement of 115 Volts at 60 Cycles, while Catalog K2 (1942) through Catalog M (1951) lists the range of 105-125 Volts at 60 Hz.

    Regarding the Strobotac's Accuracy, Catalog K1 (1939) through Catalog M (1951) list +/- 1% of the dial reading above 900 rpm when the Strobotac is standardized in terms of a frequency controlled power line.

    Regarding the Combination of the Strobotac Type 631-B and Strobolux Type 648-A, it has all the advantages of the Strobotac itself plus the feature of high-intensity illumination.

  • Net weight (2.2 lb = 1 kg)
  • 10 lb (10 lb 0 oz) / 4.540 kg
  • Price in first year of sale
  • 95.00 USD
  • Mentioned in
  • - - Manufacturers Literature (General Radio Catalog K1 (May 1939) through Catalog M (October 1951))
  • Author
  • Model page created by Peter Murguia. See "Data change" for further contributors.

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