Search results
Results from the WOW.Com Content Network
Wireless telegraphy or radiotelegraphy is the transmission of text messages by radio waves, analogous to electrical telegraphy using cables. [1] [2] Before about 1910, the term wireless telegraphy was also used for other experimental technologies for transmitting telegraph signals without wires.
The electric telegraph was slower to develop in France due to the established optical telegraph system, but an electrical telegraph was put into use with a code compatible with the Chappe optical telegraph. The Morse system was adopted as the international standard in 1865, using a modified Morse code developed in Germany in 1848. [1] The ...
Up until about 1910 the term wireless telegraphy also included a variety of other experimental systems for transmitting telegraph signals without wires, including electrostatic induction, electromagnetic induction and aquatic and earth conduction, so there was a need for a more precise term referring exclusively to electromagnetic radiation ...
Before the discovery of electromagnetic waves and the development of radio communication, there were many wireless telegraph systems proposed and tested. [4] In April 1872 William Henry Ward received U.S. patent 126,356 for a wireless telegraphy system where he theorized that convection currents in the atmosphere could carry signals like a telegraph wire. [5]
Ericsson's Understanding Telecommunications at the Wayback Machine (archived April 13, 2004) (Ericsson removed the book from their site in September 2005) VoIP, Voice over Internet Protocol and Internet telephone calls; Free Telco Dictionary
[1] [2] Spark-gap transmitters were the first type of radio transmitter, and were the main type used during the wireless telegraphy or "spark" era, the first three decades of radio, from 1887 to the end of World War I. [3] [4] German physicist Heinrich Hertz built the first experimental spark-gap transmitters in 1887, with which he proved the ...
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
A telegraph system consisted of two or more geographically separated stations linked by wire supported on telegraph poles. A message was sent by an operator in one station tapping on a telegraph key, which sent pulses of current from a battery or generator down the wire to the receiving station, spelling out the text message in Morse code.