• Country
• United States of America (USA)

• Manufacturer / Brand
• Grigsby-Grunow (-Hinds) Co. (Majestic pre 1933); Chicago (IL)

• Year
• 1929/1930

• Category
• Broadcast Receiver - or past WW2 Tuner

• Radiomuseum.org ID
• 97789

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

• Number of Tubes
• 8

• Valves / Tubes
• 27 27 27 27 27 45 45 80

• Main principle
• TRF without regeneration; 1 AF stage(s); Neutrodyne

• Tuned circuits
• 5 AM circuit(s)

• Wave bands
• Broadcast only (MW).

• Power type and voltage
• Alternating Current supply (AC) / Adjustment plate for 105, 115 and 125 Volt

• Loudspeaker
• Electro Magnetic Dynamic LS (moving-coil with field excitation coil) / Ø 10 inch = 25.4 cm

• Material
• Wooden case

• from Radiomuseum.org
• Model: Majestic 90 Ch= 90-B - Grigsby-Grunow -Hinds Co.

• Shape
• Console, Lowboy (legs < 50 %).

• Dimensions (WHD)
• 27 x 50.5 x 18 inch / 686 x 1283 x 457 mm

• Notes
• The model Majestic 90 is a console (lowboy stretcher base) with the chassis 90-B - often incorrectly called 90-B after the chassis. The chassis 90-B comes for 50-60 cycles or 25-40 cycles AC. Reason: There are two different values for the power supply: 3 condensers for 2 MF or two of them for 4 MF (for 25-40 cycles). For the antenna there is a local distance switch.
  
  The chassis 90-B from Grigsby-Grunow Co. has a 5 gang variable condensator for tuning the T.R.F. balanced circuit with a single control. The selectivity control or trimmer functions by varying the inductance of the antenna input coil and permits adjusting the input circuit to exact resonance with the other tuned circuits. The detector tube feeds (via R.F. choke) directly the transformer for the push-pull output which drive the so called "Super-Dynamic Speaker" model G-3 from Grigsby-Grunow Company in Chicago. The models Majestic 90, Majestic 91 and Majestic 93 with its different cases use the same chassis 90-B.

• Price in first year of sale
• 116.50 $

• Circuit diagram reference
• Rider's Perpetual, Volume 1 = 1931/1934 (for 1919-1931)

• Literature/Schematics (1)
• Beitman Radio Diagrams, Vol. 01, 1926-1938

• Literature/Schematics (2)
• Radio Broadcast, Apr 1930, p. 354

• Author
• Model page created by Walter Wiesmüller † May 2012. See "Data change" for further contributors.

• Other Models

• Here you find 201 models, 122 with images and 157 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Grigsby-Grunow (-Hinds) Co. (Majestic pre 1933); Chicago (IL)