• Paese
• USA (Stati Uniti d'America)

• Produttore / Marca
• Bunnell & Co., J.H.; Kings Park, NY

• Anno
• 1917 ??

• Categoria
• Modulo per radio pre 1926 (non un particolare, nessun tasto)

• Radiomuseum.org ID
• 334763

Clicca sulla miniatura dello schema per richiederlo come documento gratuito.

• Principio generale
• RF-Circuit or wave trap (separate, can also be an antenna with amp.)

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

• Tensioni di funzionamento
• Alimentazione non richiesta

• Altoparlante
• - - Nessuna uscita audio.

• Materiali
• Mobile in legno

• Radiomuseum.org
• Modello: Loose coupler - Bunnell & Co., J.H.; Kings

• Forma
• Diverse forme (descritte nelle note).

• Dimensioni (LxAxP)
• 14 x 5 x 5.5 inch / 356 x 127 x 140 mm

• Annotazioni
• 1. This is an loose coupler manufactured by the well known J.H. Bunnell & Co. pre 1919. The tuner comes from the Harold Greenwood wireless radio collection. Its paper Greenwood tag is undamaged and affixed to the underside of the base.
  2. The crystal receiver that use this coupler (see schematic) tunes from 600 KHz to 1410 KHz with the indoor 10 ft. antenna and a ground connection. With the moving coil completely outside and higher impedance static coil (left side) and moving coil switch at 0 position (right) the receiver tunes at 600 KHz. When moving sliding coil inside, the tuned frequency increase without touching any switch or variable capacitor. The tuned frequency increase also when the switch of the static coil is moved toward right, decreasing his inductance.
  3. A vintage “de Forest Crosley” 2 tube amplifier (2 x 201A tubes) is used on the test bench, in addition to high impedance (2000 ohms) headphones, as seen in related photos. 
  4. Measurements with a Rohde & Schwarz SM300 signal generator with the corresponding adapter for the impedance of a long wire antenna, shows a sensibility of around – 35 dBm over the AM band, with a decent signal to noise ratio in the headphones when the “de Forest Crosley” 2 tube amplifier is used. 

• Peso netto
• 1.750 kg / 3 lb 13.7 oz (3.855 lb)

• Autore
• Modello inviato da Serioja Tatu. Utilizzare "Proponi modifica" per inviare ulteriori dati.

• Altri modelli

• In questo link sono elencati 39 modelli, di cui 39 con immagini e 2 con schemi.
  Elenco delle radio e altri apparecchi della Bunnell & Co., J.H.; Kings Park, NY