Fil:Western Electric double button carbon microphone.jpg

Page contents not supported in other languages.
Fra Wikipedia, den frie encyklopædi

Fuld opløsning(939 × 1.319 billedpunkter, filstørrelse: 420 KB, MIME-type: image/jpeg)


Denne fil er fra Wikimedia Commons

Beskrivelse

Beskrivelse
English: Western Electric Model 357 double button carbon microphone in 1B housing, used at WFBM, the first radio station in Indianapolis, Indiana, USA, from its founding in 1924. The double button microphone was developed around 1921 by Western Electric and was extremely widely used as a broadcast and recording microphone through the 1920s because it had significantly lower noise and harmonic distortion. It is often called the "ring and spring" micrphone, as it is often seen in period photos with its cover removed. as a small microphone cylinder suspended in the center of a metal ring by springs. Carbon microphones consist of a cell containing carbon granules between two electrodes in contact with a diaphragm, but they have high harmonic distortion because the change in resistance of the carbon is nonlinear, different under compression than under tension. The double button design used two carbon cells in contact with the diaphragm on either side. They were connected to a battery and center-tapped audio transformer in a "push-pull" circuit, which canceled even-order harmonic distortion. The stiff duralumin diaphragm had a small excursion which further reduced distortion and high resonant frequency and air damping which gave it a flatter frequency response. However the cost of this higher fidelity was that it had very low output.

Caption of label card: "Announcers at WFBM, Indianapolis were using this microphone when the enterprise became Indianapolis' first successful radio station in 1924"
Dato (UTC)
Kilde This file was derived from: Radio equipment - Indiana State Museum - DSC00410.JPG
Forfatter
Andre versioner This image is a derivative work of the following images: *File:Radio_equipment_-_Indiana_State_Museum_-_DSC00410.JPG licensed with PD-self **2011-04-02T17:01:39Z Daderot 4320x3240 (4479319 Bytes)
Dette er et retoucheret billede, hvilket betyder, at det er blevet digitalt ændret fra sin oprindelige version. Ændringer: Cropped out everything except microphone. Originalen kan ses her: Radio equipment - Indiana State Museum - DSC00410.JPG. Ændringer blev udført af Chetvorno.


Licensering

Public domain Jeg, indehaveren af ophavsretten til dette værk, udgiver dette værk som offentlig ejendom. Dette gælder i hele verden.
I nogle lande er dette ikke juridisk muligt. I så fald:
Jeg giver enhver ret til at anvende dette værk til ethvert formål, uden nogen restriktioner, medmindre sådanne restriktioner er påkrævede ved lov.

Captions

Tilføj en kort forklaring på en enkelt linje om hvad filen viser

Elementer som er med i denne fil

afbilder

Filhistorik

Klik på en dato/tid for at se filen som den så ud på det tidspunkt.

Dato/tidMiniaturebilledeDimensionerBrugerKommentar
nuværende23. jan. 2014, 13:31Miniature af versionen fra 23. jan. 2014, 13:31939 × 1.319 (420 KB)Chetvorno{{Information |Description ={{en|1=Western Electric Model 357 double button carbon microphone in 1B housing }} |Source ={{Derived from|Radio_equipment_-_Indiana_State_Museum_-_DSC00410.JPG|display=50}} |Author =*Original work [[:File...

Den følgende side bruger denne fil:

Global filanvendelse

Følgende andre wikier anvender denne fil:

Metadata