• Paese
• USA (Stati Uniti d'America)

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

• Anno
• 1928

• Categoria
• Radio (o sintonizzatore del dopoguerra WW2)

• Radiomuseum.org ID
• 199205

Clicca sulla miniatura dello schema per richiederlo come documento gratuito.

• Numero di tubi
• 8

• Valvole
• UX226 UX226 UX226 UY227 UX226 UX171A UX171A UX280

• Principio generale
• Ricevitori speciali; 3 Stadi BF

• N. di circuiti accordati
• 4 Circuiti Mod. Amp. (AM)

• Gamme d'onda
• Solo onde medie (OM).

• Tensioni di funzionamento
• Alimentazione a corrente alternata (CA) / 90-130 Volt

• Altoparlante
• AP elettrodinamico (bobina mobile e bobina di eccitazione/di campo)

• Materiali
• Mobile in legno

• Radiomuseum.org
• Modello: Majestic 72 Ch= 70 - 7A [Early] - Grigsby-Grunow -Hinds Co.

• Forma
• Console, con gambe d'appoggio alte (> 50%).

• Annotazioni

• One dial (primary tuning control knob) This set has a push-pull output stage using two 171A power tubes. It is made of walnut with burl walnut front panels and came with a Majestic electric power unit and Majestic dynamic power speaker.
  Model 72 can use the 7P6 or 7P3 power unit. See also Majestic model 72 with chassis 7-B.
  
  This model here shows the loudspeaker below that radio chassis and the B shows the opposite. Maybe one could chose, maybe it is typical for the two versions - we don't know yet. On the speaker unit one can read: Majestic, Power Speaker, Model G1 Serial no. 300012 (not sure, hard to see), for use with model 71, 72, 80 (not sure). The chassis reads: Majestic 7, Electric Receiver Model 70 Serial no. 7A-, Grigsby-Grunow Company, Chicago USA. The cabinet reads: Majestic, Electric Receiver, Model 72, Grigsby-Grunow Company, Chicago USA. There is a hum control adjust for minimum hum in speaker.

  This radio is a cascade of 3 individual TRF stages, each with its own feedback coil forming a Wheatstone bridge acting as a Hazeltine neutralization for the triode (described as the RFL circuit in contemporary sources). The feedback polarity is reversed with respect to the signal polarity through the C_ag Miller-capacitance, in effect neutralising the triode tendency to oscillate.

• Prezzo nel primo anno
• 210.25 $

• Fonte esterna dei dati
• Carlos Vázquez-Hancock

• Bibliografia
• October 27, 1928 Radio Doings magazine advertisement page 30

• Autore
• Modello inviato da Ernst Erb. Utilizzare "Proponi modifica" per inviare ulteriori dati.

• Altri modelli

• In questo link sono elencati 201 modelli, di cui 122 con immagini e 156 con schemi.
  Elenco delle radio e altri apparecchi della Grigsby-Grunow (-Hinds) Co. (Majestic pre 1933); Chicago (IL)