Jump to content

File:Western Electric double button carbon microphone.jpg

Page contents not supported in other languages.
This is a file from the Wikimedia Commons
From Wikipedia, the free encyclopedia

Original file (939 × 1,319 pixels, file size: 420 KB, MIME type: image/jpeg)

Summary

Description
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"
Date (UTC)
Source This file was derived from: Radio equipment - Indiana State Museum - DSC00410.JPG
Author
Other versions 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)
This is a retouched picture, which means that it has been digitally altered from its original version. Modifications: Cropped out everything except microphone. The original can be viewed here: Radio equipment - Indiana State Museum - DSC00410.JPG. Modifications made by Chetvorno.


Licensing

Public domain I, the copyright holder of this work, release this work into the public domain. This applies worldwide.
In some countries this may not be legally possible; if so:
I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.

Captions

Add a one-line explanation of what this file represents

Items portrayed in this file

depicts

23 January 2014

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current11:31, 23 January 2014Thumbnail for version as of 11:31, 23 January 2014939 × 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...

The following page uses this file:

Global file usage

The following other wikis use this file:

Metadata