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Microphone - New Wilson Electrical Manufacturing Co, Magnetic Microphone Bar, 1927
Reg. No: HT 26207
- Summary:
- Carbon microphone used in association with a headphone (not present) to form a valveless amplifier. It was probably manufactured by New Wilson Electrical Manufacturing Co. Ltd in 1927.
The bar replaces the diaphragm of a headphone earpiece so the bar now vibrates instead of the diaphragm. The earpiece is connected to the output of the radio (usually a crystal set). The movement of the microphone bar changes the resistance between the microphone terminals (ie the resistance between the screw and the carbon). A pair of headphones (for listening) is connected via the microphone terminals to a battery.
A control knob allows adjustment of the sensitivity of the microphone part. - Description:
- A rectangular metal shaped object with a black disc attached to one side with a screw. There is one terminal on the body and another on the black disc.
Internally there is a carbon block mounted between two nickel plated ends joined by a blunt ended oval shaped piece of magnetic material. The screw, on the opposite side, can be adjusted to optimise the pressure between the carbon and the contact for maximum sensitivity.
| Discipline: | Technology |
| Dimensions: | 55 mm (Height), 25 mm (Width) |
More information
| Tagged with: | radios |
| Themes this item is part of: | Information & Communication Collection |
| Primary Classification: | COMMUNICATIONS |
| Secondary Classification: | Radio |
| Tertiary Classification: | transmitters |
| Inscriptions: | On metal body: " MAGNETIC / MICROPHONE / BAR ", " PATENT No / 248581-25 " |
| Manufacturer (Probable): | New Wilson Electrical Manufacturing Co. Ltd., London, England, 1927 Radiomuseum http://www.radiomuseum.org/r/newwilson_microphone_bar_amplifier.html accessed 22 Nov 2011 |
| References: | Radiomuseum http://www.radiomuseum.org/r/newwilson_microphone_bar_amplifier.html accessed 22 Nov 2011 |
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