File:Ampli BF-colorized.jpg
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[edit]DescriptionAmpli BF-colorized.jpg |
Français : Un des premiers récepteurs radio audionconstruit par l'inventeur dutube à vide audion , Lee De Forest , vers 1914. L'audion, la première triode , fut le premier tube électronique capable d' amplifier . Bien qu'inventé en 1906, la capacité d'amplification de l'audion n'a été reconnue qu'en 1911-1912, c'était donc l'un des premiers récepteurs radio amplificateurs. Il apparaît dans un article de De Forest démontrant à ses collègues ingénieurs que l'audion n'était pas seulement un détecteur radio, mais avait également la capacité d'amplifier un signal. Cet appareil n'était pas un récepteur complet, seulement un détecteur et un amplificateur audio à deux étages; en cours d'utilisation, il était connecté à la sortie d'une section "tuner" qui sélectionnait la station à recevoir. Les deux tubes à audion sont visibles, montés à l'envers, comme les audions l'étaient habituellement, de sorte que leurs filaments délicats ne s'affaissent pas sous leur propre poids et ne touchent pas la grille. Le bouton central contrôlait le courant du filament; le multipoint inférieur commute la tension de la plaque. Le gain de ces tubes primitifs était faible; la source revendique des gains de puissance allant jusqu'à 5. Une évacuation inadéquate a laissé un air résiduel considérable dans l'audion qui s'est ionisé, provoquant un fonctionnement erratique et raccourcissant la durée de vie du filament. Modifications de l'image: suppression des artefacts d'aliasing (bandes diagonales) de la numérisation de l'image en demi-teinte à l'aide du filtre Gimp FFT. English: An early audion radio receiver built by the inventor of the audion vacuum tube, Lee De Forest, around 1914. The audion, the first triode, was the first electronic tube that was able to amplify. Although invented in 1906, the amplifying ability of the audion was not recognized until 1911-1912, so this was one of the first amplifying radio receivers. It appears in a paper by De Forest demonstrating to his fellow engineers that the audion was not just a radio detector but also had the ability to amplify a signal. This device was not a complete receiver, only a detector and two stage audio amplifier; in use it was connected to the output of a "tuner" section which selected the station to be received. The two audion tubes are visible, mounted upside down, as audions usually were, so that their delicate filaments did not sag under their own weight and touch the grid. The center knob controlled the filament current; the lower multipoint switch the plate voltage. The gain of these primitive tubes was low; the source claims power gains of up to 5. Inadequate evacuation left considerable residual air in the audion which ionized, causing erratic operation and shortening the life of the filament. Alterations to image: removed aliasing artifacts (diagonal stripes) from scanning of halftone image using Gimp FFT filter. |
Date | Prior to March 1914 |
Source | Downloaded 03-26-2013 from Lee De Forest The Audion - Detector and Amplifier in Proc. of the Inst. of Radio Engineers ( Institute of Radio Engineers, NY) Vol. 2, No. 1, March 1914, p.18, fig. 4 on Google Books |
Author | Lee De Forest |
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[edit]Public domainPublic domainfalsefalse |
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current | 18:02, 10 October 2020 | ![]() | 1,600 × 1,228 (773 KB) | F1jmm (talk | contribs) | Application |
16:56, 10 October 2020 | ![]() | 1,242 × 1,044 (363 KB) | F1jmm (talk | contribs) | Uploaded own work with UploadWizard |
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File change date and time | 10 oct. 2020 20:00:49 GMT+02:00 |
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