Meissner_radiotelephone_transmitter.jpg
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Summary
Description Meissner radiotelephone transmitter.jpg |
English:
One of the earliest
vacuum tube
radiotelephone
transmitters
, built by German scientist
Alexander Meissner
in 1913. In a historic test in June 1913, Meissner used it to transmit voice 36 km (24 mi) from Berlin to Nauen, Germany. It used a mercury vapor
triode
vacuum tube
(large tube visible)
developed beginning in 1906 (approximately at the same time as De Forest's
Audion
tube) by Austrian engineers Robert von Lieben and Eugen Riesz. The large Lieben-Riesz tube
(right)
was used in the Meissner oscillator transmitter circuit which he had developed earlier that year, while the receiving circuit used a smaller Fleming valve
(left)
. It transmitted on a wavelength of 600 m (500 kHz) with an output power of 12 W with 440 V on the plate, modulated with a carbon microphone in the antenna lead. H. J. Round noted that when the Leiben tube was used at such power levels, the tube lasted only 10 minutes before the
filament
burned out due to bombardment by mercury ions.
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Date | |
Source | Downloaded 27 August 2013 from Alfred N. Goldsmith (November 1917) "Radio Telephony, Article 11", The Wireless Age (Wireless Press, Inc., New York), Vol. 5, No. 2, p. 110, fig. 139 on Google Books |
Author | Alfred N. Goldsmith |
Licensing
Public domain Public domain false false |
This media file is in the
public domain
in the
United States
. This applies to U.S. works where the copyright has expired, often because its first
publication
occurred prior to January 1, 1929, and if not then due to lack of notice or renewal. See
this page
for further explanation.
|
||
This image might not be in the public domain outside of the United States; this especially applies in the countries and areas that do not apply the
rule of the shorter term
for US works, such as Canada, Mainland China (not Hong Kong or Macao), Germany, Mexico, and Switzerland. The creator and year of publication are essential information and must be provided. See
Wikipedia:Public domain
and
Wikipedia:Copyrights
for more details.
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