Spark transmitters and the crystal receivers used to receive them were simple enough that they were widely built by hobbyists. During the first decades of the 20th century this exciting new high tech hobby attracted a growing community of “radio amateurs”, many of them teenage boys, who used their homebuilt sets recreationally to contact distant amateurs and chat with them by Morse code, and relay messages. Low-power amateur transmitters (“squeak boxes”) were often built with ignition coils from early automobiles such as the Ford Model T …
The Images below are from Hamfesters Radio Club Chicago Ill …. W9AA
First defined in ICAO publication “Doc 6100-COM/504/1” and in “ICAO Procedures for Air Navigation Services, Abbreviations and Codes (PANS-ABC)” [Doc8400-4] (4th edition 1989), the majority of the Q codes have slipped out of common use; for example today reports such as QAU (“I am about to jettison fuel”) and QAZ (“I am flying in a storm”) would be voice or computerized transmissions. But several remain part of the standard ICAO radiotelephony phraseology in aviation. These are also part of ACP131, which lists all ITU-R Q Codes, without grouping them by aeronautical/marine/general use.
Thomas Edison patented Electromagnetic Induction, he called it “Grasshopper Telegraphy”. Which allowed telegraphic signals to jump the short distance between a running train and telegraph wires running parallel to the tracks. The system was successful technically but not economically. During the Great Blizzard of 1888, this system was used to send and receive wireless messages from trains buried in snow drifts. The disabled trains were able to maintain communications via their Edison induction wireless telegraph systems, perhaps the first successful use of wireless telegraphy to send distress calls. Edison would also help to patent a ship-to-shore communication system based on electrostatic induction. This is about all that is written about this but for more info and history “Click Here for Wikipedia“.
Examples of dielectric media are glass, air, paper, plastic, ceramic, and even a semiconductordepletion region chemically identical to the conductors. From Coulomb’s law a charge on one conductor will exert a force on the charge carriers within the other conductor, attracting opposite polarity charge and repelling like polarity charges, thus an opposite polarity charge will be induced on the surface of the other conductor. The conductors thus hold equal and opposite charges on their facing surfaces, and the dielectric develops an electric field.
Traffic passing by formal relay (via amateur radio) originates from the founding of the American Radio Relay League. The NTS as it exists today was first outlined by George Hart, W1NJM (died 24 March 2013) in “New National Traffic Plan: ARRL Maps New Traffic Organization for All Amateurs” as part of the September 1949 issue of QST. While traffic passing between amateur radio operators was nothing new, Hart’s system extended coverage of traffic capability in a uniform manner across the U.S. and Canada, creating formal section and area nets devoted to handling NTS-organized traffic.
Jan Rudolph Deiman and Adriaan Paets van Troostwijk used, in 1789, an electrostatic machine to make electricity which was discharged on gold electrodes in a Leyden jar with water. In 1800 Alessandro Volta invented the voltaic pile, and a few weeks later William Nicholson and Anthony Carlisle used it for the electrolysis of water. When Zénobe Gramme invented the Gramme machine in 1869 electrolysis of water became a cheap method for the production of hydrogen. A method of industrial synthesis of hydrogen and oxygen through electrolysis was developed by Dmitry Lachinov in 1888.
The Leyden Jar, named after the city Leiden, the Leyden jar could store high voltage, (Despite its mundane and safe appearance, the Leyden jar is a high voltage device, and it is estimated that at a maximum the early Leyden jars could collect electrical energy from friction in a range from 20,000 to 60,000 volts ).
The Leyden Jar has metal inside and outside of the container then partially filled with water or other type of liquid, the cap has a nail protruding through it and a ground attached to the outer metal shell…
CW (Continuous Wave), ITW (Interrupted Continuous Wave), or on-off keying are a recognized emission type known as A1A by the International Telecommunication Union. Continuous Wave replaced – Damped Wave completely in 1920.