• Year
  • 1929/1930
  • Category
  • Broadcast Receiver - or past WW2 Tuner
  • Radiomuseum.org ID
  • 97796

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

 Technical Specifications

  • Number of Tubes
  • 8
  • 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 91 Ch= 90-B - Grigsby-Grunow -Hinds Co.
  • Shape
  • Console, Lowboy (legs < 50 %).
  • Notes
  • The "Majestic 91" has an "Early English style cabinet" with stretcher base. It was made with two slightly different chassis outfits, the chassis 90 or the chassis 90-B.
    The chassis 90 uses separate Power Supply 9P3 or 9P6. THe Chassis 90-B has an integral Power Supply. This is one of the models using the chassis 90-B - often incorrectly named model Majestic 90-B. 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 and 90-B from Grigsby-Grunow Co. have 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, while chassis 90 is used in console models 91 and 92. This model 91 here is the only one where both chassis versions were applied. Since there is no way to tell from pictures which version found use, we decided (as an exception) to mention both chassis in one model together.

    Note also that the pictures currently associated with this model have some differences in cabinet style.

  • Price in first year of sale
  • 137.50 $
  • Circuit diagram reference
  • Rider's Perpetual, Volume 1 = 1931/1934 (for 1919-1931)
  • Literature/Schematics (2)
  • Radio Broadcast, Apr 1930, p. 354

 Collections | Museums | Literature

Collections

The model Majestic 91 is part of the collections of the following members.

 Forum

Forum contributions about this model: Grigsby-Grunow -: Majestic 91 Ch= 90-B

Threads: 1 | Posts: 5

In the web Page majestic_91_ch_90_b90, The Cabinet posted by Aleksander Kowal, does not apear to be the corect one. The chasis is correct though. Please let me know your thoughts on this.

Grant Bruner, 06.Jan.20

Weitere Posts (5) zu diesem Thema.