1888 on: Radio development begins in earnest
In 1888 the German Heinrich Hertz conclusively proved Maxwell's prediction that electricity could travel in waves through the atmosphere. Unlike Hughes, the extensive and systematic experiments into radio waves that Hertz conducted were recognized and validated by inventors around the world. Now, who would take take these findings further and develop a true radio?
Dozens and dozens of people began working in the field after Hertz made his findings. It is a miserable job to decide what to report on from this period, with people like Tesla, Branly, and yes, even folks like Nathan B. Stubblefield (external link), claiming to have invented radio. Typical of these events is Jagadis Chandra Bose (external link -- 817K!) demonstrating in 1895 electromagnetic waves "by using them to ring a bell remotely and to explode some gunpowder." While not inventing radio, any more than Edison invented the incadesent light bulb, Marconi did indeed establish the first successful and practical radio system. Starting in 1894 with his first electrical experiments, and continuing until 1901 when his radio telegraph system sent signals across the Atlantic ocean, Marconi fought against every kind of discouragement and deserves lionizing for making radio something reliable and useful.
Don Kimberlin (internal link) now questions Marconi's 1901 claim. It seems likely Marconi did not make a transatlantic radio reception that year. Read Kimberlin's page or download the .pdf file discussing this by clicking here.
Ships were the first wireless mobile platforms. In 1901 Marconi placed a radio aboard a Thornycroft steam powered truck, thus producing the first land based wireless mobile. (Transmitting data, of course, and not voice.) Arthur C. Clarke says the vehicle's cylindrical antenna was lowered to a horizontal position before the the wagon began moving. Marconi never envisioned his system broadcasting voices, he always thought of radio as a wireless telegraph. That would soon change.
Visit Arthur C. Clarke's Time Line of Communication at http://www.acclarke.co.uk/1900-1909.html This link no longer seems to be working.
On December 24, 1906, the first radio band wave communication of human speech was accomplished by Reginald Fessenden over a distance of 11 miles, from Brant Rock, Massachusetts, to ships in the Atlantic Ocean. Radio was no longer limited to telegraph codes, no longer just a wireless telegraph. This was quite a milestone, and many historians regard the radio era as beginning here, at the start of the voice transmitted age.
Coils of wire, induction at work, changing the frequency of a line, crystal receivers demonstrate many electrical principles. I've built small crystal sets myself and you can find the kits in many places. They are fascinating, operating not off of a battery but only by the energy contained in the captured radio wave. Just the power of a received radio wave, nothing more.
As Morgan put it, "Radio receivers with sensitive, inexpensive crystal detectors, such as this double slide tuner crystal set, appeared as early as 1904, and were used by most amateurs until the early Thirties, when vacuum tubes replaced crystals. An oatmeal box was a favorite base upon which to wind the wire coils." (Click here for a much clearer, larger image.)
Visit this site soon, plans to build, kits to buy, good information on crystal radios:
Crystal Radio Connections: blending art and science
