• Pays
• Etats-Unis

• Fabricant / Marque
• Bowman's Sons, Ezra F.; Lancaster (PA)

• Année
• 1917 ??

• Catégorie
• Poste à détecteur (diode ou cristal, pas de lampes)

• Radiomuseum.org ID
• 155549

• Principe général
• Détecteur à galène ou semi-conducteur

• Gammes d'ondes
• PO et GO en UNE SEULE bande (rare)

• Tension / type courant
• Pas d'alimentation nécessaire

• Haut-parleur
• - Pour casque ou amplificateur BF

• Matière
• Boitier en bois

• De Radiomuseum.org
• Modèle: Watchmakers Crystal Radio Set - Bowman's Sons, Ezra F.;

• Forme
• Modèle de table générique

• Dimensions (LHP)
• 16.5 x 6 x 12 inch / 419 x 152 x 305 mm

• Remarques
• Bowman Watchmakers Crystal Radio Set;
  Radio set mounted on wooden panel. W.M.Murdock variable and fixed (phone) condenser. Loose coupler (Bowman or Murdock 337?) with slider on primary coil & eight secondary tappings. Bowman's crystal detector (1917).
  
  In 2009 such a set was sold (eBay) for only 643 US$. The reason for the moderate price was the modification by addition of a much later Sodion D_21 tube. That is a detector tube which could even oscillate (the predecessors were unable to do), but never a sole amplifier and usually it was operated inverted (base up, dome down) due to the sodium filling. The pictured tube and its socket are looking like a modification to replace the crystal with a tube. The crystal is no longer connected! The wiring is not convincing: There are no binding posts for A and B supply? Tube connections do not make sense, and the wiring craftsmanship is doubtful (see e.g. binding posts of variable condenser).
  Furthermore Sodion tubes were not available before 1923, and the D21 even later, while the basic crystal set here is certainly pre 1920. All its components were available in 1917 and before. Conclusion: Crystal set around 1917, modified for tube detector (unclear whether diode or audion was intended). The unconnected crystal excludes an added amplifier stage. The missing battery supply elements may point to an unfinished modification. Looks like an attempt of visual upgrading to look more attractive.

• Schémathèque (1)
• Crystal Clear Volume 2 (p.106 for crystal det.)

• Auteur
• Modèle crée par d'un membre de A. Voir les propositions de modification pour les contributeurs supplémentaires.

• D'autres Modèles

• Vous pourrez trouver sous ce lien 1 modèles d'appareils, 1 avec des images et 0 avec des schémas.
  Tous les appareils de Bowman's Sons, Ezra F.; Lancaster (PA)