Concite Galena Crystal

Conradi & Braun Ltd.; London

Dati
Forum
Immagini
Collezioni

  • Anno
  • 1924
  • Categoria
  • Radio a galena (a cristallo o a diodo, senza valvole o transistores)
  • Radiomuseum.org ID
  • 364677

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 Specifiche tecniche

  • Principio generale
  • Rivelazione a galena / semi-conducteur
  • Gamme d'onda
  • - senza
  • Tensioni di funzionamento
  • Alimentazione non richiesta
  • Materiali
  • Vari materiali
  • Radiomuseum.org
  • Modello: Concite Galena Crystal - Conradi & Braun Ltd.; London
  • Forma
  • Diverse forme (descritte nelle note).
  • Annotazioni

  • The Concite crystal, a brand of galena (PbS) marketed by Messrs. Conradi & Braun of London and trademarked in October 1923 for use as a wireless detector in crystal radios, was sold along with its accompanying cat's-whisker enclosed in a small, sealed glass tube for ease of use and protection. This common packaging method ensured the delicate crystal surface remained clean and the contact point stable, although one contemporary review noted that the included cat's-whisker itself was unsatisfactory due to having too small a spiral.

    Characteristic Technical Detail
    Material/Appearance Galena (PbS) of normal appearance.
    Rectification Loss Low, measured at approximately 0.5% for medium voltages.
    Rectification Bend Point The characteristic "bend" in the current-voltage curve occurs at approximately 0.2 volt, suggesting that the use of a potentiometer would be advantageous for achieving maximum sensitivity.
    Linearity (Curve Above Bend) The curve immediately above the bend is described as "nice and straight," indicating that it provides proportional rectification for signals with fairly large inputs.
    Resistance Fairly high, measured at approximately 2,700 Ω at 1V.
    Sensitivity Demonstrated good results both in signal strength and in the proportion of sensitive spots. The crystal was reported to be sensitive right through its surface.
    Quality Control Of the points tested, 40% were good and 60% were fair, suggesting generally reliable quality.
    Physical Properties The crystal was noted for not being unduly brittle.
    Associated Component The included cat's-whisker was deemed unsatisfactory due to having a spiral that was "much too small," though the crystal itself performed to the "ordinary average for a good galena" when paired with a better whisker.

     

  • Prezzo nel primo anno
  • 0.08 GB £
  • Letteratura / Schemi (1)
  • -- Original prospect or advert (The Wireless Engineer, Oct 1924, P. 49)
  • Autore
  • Modello inviato da Gary Cowans. Utilizzare "Proponi modifica" per inviare ulteriori dati.

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