Jump to content

File:Marconi 1897 spark gap transmitter.jpg

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

Marconi_1897_spark_gap_transmitter.jpg (429 × 286 pixels, file size: 27 KB, MIME type: image/jpeg)

Summary

Description
English: Photo of early spark-gap radio transmitter used by Guglielmo Marconi during pioneering wireless telegraphy experiments at La Spezia, Italy in July 1897. It used an induction coil (right) powered by batteries in the box (rear) to apply pulses of high voltage to a Righi type spark gap (left), creating sparks which excited brief oscillating currents in a 75 ft. vertical antenna attached to the spark gap, ending in an 8 foot square sheet of metal. The operator turns the transmitter on and off rapidly with the telegraph key (at right) to spell out messages in Morse code. On July 18, 1897 in tests for the Italian Marine Ministry, it successfully transmitted signals 16.3 km (14 miles) from St. Bartholomew to a ship in the Sea of Spezia (source, p.337-339).
Date
Source Downloaded 5 March 2010 from Domenico Mazzotto (1906) Wireless Telegraphy and Telephony, translated by Selimo R. Bottone, Whittaker & Co., New York, p.338, fig.236 on Google Books
Author Guglielmo Marconi
Permission
(Reusing this file)
Public domain - Marconi died in 1920

Licensing

Public domain

This work is in the public domain in its country of origin and other countries and areas where the copyright term is the author's life plus 70 years or fewer.


You must also include a United States public domain tag to indicate why this work is in the public domain in the United States.
This file has been identified as being free of known restrictions under copyright law, including all related and neighboring rights.

Annotations
InfoField
This image is annotated: View the annotations at Commons

Captions

Guglielmo Marconi's early radio transmitter

Items portrayed in this file

depicts

File history

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

Date/TimeThumbnailDimensionsUserComment
current13:53, 5 March 2010Thumbnail for version as of 13:53, 5 March 2010429 × 286 (27 KB)Chetvorno{{Information |Description={{en|Photo of early spark-gap transmitter used by Guglielmo Marconi during pioneering wireless telegraphy experiments at La Spezia in July 1897. It used a Righi type oscillator ''(left)''.}} |Source=Downloaded 2010-03-05 f

The following 2 pages use this file:

Global file usage

The following other wikis use this file: