Although Leyden Jars and Coher Detectors were soon replaced with Condensers and Crystals, and a few stations were already transmitting voice, commercial and military wireless stations were still dominated by both Arc and Spark telegraphy, up to the end of 1914 (the start of the Great War).
During the Great War the military quickly advanced the state of radio, so that by the time civilian broadcast and reception restrictions were lifted, thermionic tubes and voice transmission was the norm. The great radio boom of 1921 (the first year the baseball World Series was broadcast) saw the public snapping up manufactured radio receivers as fast as they became available. Advances came almost monthly, so that by the start of the Great Depression (at the end of 1929), radio as we know it today, including Radio Direction Finding, Radio Control, and regularly broadcast Television programming, was an everyday affair. Even RADAR, Radio Astronomy, FM, and SSB was being studied and developed.
Note that much of which was discovered and developed during this period can be applied to modern equivalency components. Newer formulations for batteries make them last longer, but they are still just batteries. Integrated circuits work the same as discreet circuits, they just fit in a smaller space. Even digital is just a throwback to early pre-analog solutions.
Up until 1915, radio was commonly referred to as Wireless, and for the most part remained in the laboratory. After 1915, wireless was commonly referred to as Radio, and was now a practical military, and later commercial, method of communications. Due to this very clear delineation, I have separated period technical books published before and after 1915 onto separate web pages. Period books that are of a peripheral nature (such as histories and regulations) are kept on yet another web page. Because it is my hope that individuals will recreate or adapt some of the circuits described in these books, I have included a web page of useful post-1929 handbooks, which provide formulas and tool handling techniques that can aid the experimenter in this endeavor.
All downloadable books appearing in this archive are FREE.