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The History of Amateur Radio

The first radio prefixes (V)

In 1906, at the first International Radiotelegraph Conference of Berlin, it was decided that call signs of stations in the international radiotelegraph system had to be formed of a group of three letters which were to be distinguishable from one another.

On July 5, 1912, pushed by the Radio Act that requested the identification of all users of the spectrum, the second International Radiotelegraphic Conference took place in London and allocated to each Member State a call sign made of 2 or 3 letters. Discussions extended over one month and 9 sessions. After approval by all Member States, the Convention entered into force on July 1, 1913.

Here is the full original document in French (propositions, corrections and final protocol), the same file restricted to the regulation approved between stakeholders, and its bilingual French/English version available on ITU portal.

Following this conference, the Bureau of the International Telegraph Union of Bern sent three Circulars to the Member States regarding the new allocation of call signs (circular No.37 - 31 August 1912, No.45 - 21 December 1912 and No. 55 - 23 April 1913), completed with an appendix of 145 pages listing all possible call sign combinations (Cf. this Circular, end p7). This directory was available to all national administrations, all compagnies using the telegraph and on request to private users.

In the frame of this new Convention, in the U.S.A., the Bureau of Navigation was assigned the responsibility of licensing all radio stations, including the existing ones using a two-letter call sign. However during some years the U.S. Department of Commerce used a different schema for amateurs and land stations than for ships and commercial stations.

As listed in the "Radio Call letter" C11.2:R11 published on May 9, 1913 each amateur received a call sign constitued of 3 characters : a number depending on the radio district (e.g. 1 for Boston, including Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, 2 for New York, etc) and two letters while broadcasters and ships were assigned a three-letter call sign. It is so that soon ARRL was assigned the call sign 1MK, Fred Schnell, 1MO, and Hiram Percy Maxim, 1WH among the most famous amateurs.

All states that signed the Convention were invited to do the same but their action plan remained pending for several years. The reason was simple : in most countries there was no amateur experimenting radio transmissions yet. Together, in Great Britain, in France and in Belgium only a handful of skilled amateurs tested from time to time spark gap transmitters for their own curiosity while most others simply listen to the radio in the 200-meter band using a galena crystal set, nicknamed the "cat's whisker", equiped with a long wire.

So, european administrations will wait until '20s to assign the first call signs to amateurs.

The spare-time activity becomes a service

In March 1913, a severe windstorm knocked out power, telegraph and telephone lines in the US midwest, forcing the population to support a blackout during a few weeks. Thanks to battery powered, amateur stations handled routine and emergency traffic until regular service was restored. This was the first documented emergency communications in amateur radio history.

The U.S.A., due to their large population, were the first country considering that amateur radios, able to install communications means in less than 15 minutes, could also be used to service the nation in case of disaster (hurricane, severe weather, etc) and other emergency situations. 

To confirm this change of mentality, in 1915 the US amateur station 2MN discovered that the powerful Telefunken station at Sayville, Long Island, was sending information concerning Allied and neutral shipping to U-boats at sea. Thanks to the work of this amateur, the government took over the ham station. We will come back of this program in 1932 with the creation of ARES.

To read : A Tribute to Morse Telegraphy, The telegraph Office

The thrill of wireless

"Wireless is a thrilling pastime. Fancy a boy sitting in his room at home with his fingers on a telegraph key and a telephone receiver to his ear listening-in to the news of the world as it is flashed out from the great coast stations or by ships far out at sea! It's a great experience. Yet thousands of boys are doing this wonderful thing every day and night of the year, and you, my young friend, can do it as easily as they, for any boy can own a real wireless station, if he really wants to."

A. Frederick Collins, The Book of Wireless, 1915.

Sketch of a Triumph telegraph key made by J.H.Bunnell & Co in 1906.

1912 : First telegraphic stations in Congo Belge

Back in 1900, Léopold II, the King of Belgians, believed  in the success of the "télégraphie sans fil" (TSF), the wireless, and to its major role for his new colony, the Congo, in Equatorial Africa.

Marconi was invited at the Royal Palace of Laeken to discuss the possibilities to test the first wireless communications between Banana located in Belgian Congo, and Ambrisette in Portuguese Congo. Results failed and they gave up the idea in 1904. 

This is only on Mars 15, 1912 that the Ministry of Colonies decided to use the current telegraphic stations located in Congo or to set up new ones at Banana, Boma, Coquilhatville, Lisala, Stanleyville, Lowa, Kindu, Kongolo, Kikondja, Elisabethville, and Lusambo.

In 1913, the Belgian Robert Goldschmidt founded the International Wireless Commission (CITSF) which mission was to develop the research on waves propagation. On King Albert I's initiative, a high power "TSF" station was built at Laeken, Brussels, in Belgium to maintain a permanent radio contact with nationals in Congo. A similar station was set up in Congo, at Leopoldville. A communication network was established between 1913 and August 1914. 

The belgian station used an antenna farm constituted of 8 towers of 80 and 125 m high ! To power such monsters, engineers built a special engine developing 300 horsepowers that drove a 1 kHz alternator, a huge spark system (éclateur) generating the required excitation. At a few hours from the German invasion, King Albert I ordered its destruction. This was achieved by the belgian Civil engineering while German went at fiercely on the garbages, probably by frustration. Several spark systems were however hidden in a church.

At left, the wireless "TSF" type Laeken set up at Leopoldville, Congo Belge, in 1914. At right, the engine room at Laeken developing 300 horsepowers and that was partly destroyed before the German invasion. Documents UBA.

By 1916, there were 5,000 licensed US amateurs, 1000 ARRL relay stations, and 150,000 receivers in use. In the UK there were nearly 2,000 licensed and ten times less or even a handful in the other countries.

The American Radio Relay League

In the '10s amateurs learnt to work with the Audion waiting that the triode of Lee de Forest be widely distributed and accessible to amateurs. Now hams could build receivers able to discrimine signals to distances up to 530 km (350 miles) on 200 meters. But soon the Audion became a scarce and expensive device and many amateurs searched fo spares, in vain. Until Hiram Percy Maxim, 1WH, a 44 year old engineer, working with a 1-kW amateur station in Hartford, CT wanted an Audion for his receiver and was unable to find one. 

Eventually, he heard of an amateur in Springfield, MA, who had one for sale but with his station Maxim could not cover the distance of 40 km (25 miles). He had to find an intermediate station that was willing to relay his purchase offer. Maxim thought about this problem and eventually realized that to relay reliable messages on long distance a national organization was needed to coordinate and standardize message relay procedures, as well as to protect the interests of radio amateurs.

On April 6, 1914, Maxim with the backing of the Radio Club of Hartford, who appropriated $50 (of 1914 !), and some volunteers, proposed the formation of the American Radio Relay League (ARRL). Maxim developed an application form explaining the purpose of the ARRL and invited every known station in the country to join the League. 

1MK, the ARRL HQ in Hartford, CT., as displayed on the cover of QST in 1925.

Maxim, like Armstrong, was a prolific inventor. Unlike Armstrong however, Maxim was also an orator-born and convinced national magazines such as Popular Mechanics to write favorable reports about his non-profit association. Maxim also traveled to Washington, D.C., to explain the ARRL objectives to the Department of Commerce and the Commissioner of Navigation. 

His "pioneer blitz" paid off. By September, 1914, there were 237 relay stations appointed, and traffic routes were established from Maine to Minneapolis, and Seattle to Idaho. Realizing that long distances on 200 meters were not possible at that time, even with a regenerative receiver, Maxim ask the Department of Commerce to authorize special operations on 425 meters (706 Kc) for relay stations in remote areas. They granted. Boosted by the publicity, the number of amateur stations as well as the relay stations in the ARRL continued to grow.

The ARRL emphased the word "Relay",  the equivalent of the modern word "repeater", but less technical. Maxim wanted that ARRL stations handle traffic on the six main truck lines (3 N-S, 3 E-W) that served more than 150 cities.

As a pioneer exercise to test the system nationwide, in 1916 a test message was sent to the Governors of every State, and President Wilson in Washington, D.C.. The message was delivered to 34 States and the President within 60 minutes. By 1917, the system was "so refined" that a message sent from New York to California took only 45 minutes. For comparison, in 1921 a reply requested only 6.5 minutes to transmit from coast to coast ! To deal with the increasing number of relay stations, the ARRL started a little magazine, which they called QST, always alive. It constitutes today the first ham magazine read worldwide and is stronger than ever. The number of subscribers exceeded 6,000 amateurs at dawn of Great War.

'14-18 : The Great War

While the Great War against Germany began in Europe, prior to U.S.A. entry into World War I in April 1917, by order of the Chief Radio Inspector of the US Navy, the Secretary of Commerce ordered that all amateurs and other non-government radio stations shut down. The message sent to all stations asked them that all transmitting and receiving stations had to be closed and disassembled, and all antennas taken down in order to no more render operating any transmitter or receiver. Complete radio silence was to remain until the war ended and the order was revoked. So amateurs by the thousands packed away their stations.

The fact that amateurs were trained radio operators didn't go unnoticed - Maxim made all for this ! - and some 4000 hams marched off to war. More than ever the word "service" has to be emphasized. Not only hams represent a joined community but there are also of service to the public and to the nation, whatever circumstances.  

However, in a few months the 200-meter band was silent. In September 1917, with no radio activity permitted and over 80% of the amateurs at war, QST ceased publication.  

Hopefully, the madness of men ended on November 11, 1918. But the Navy didn't permit amateurs to go back on the air. They would like to keep control over all radio services, even at peacetime. A legislation was published to support the Navy objectives.

Supported by thousands hams ARRL fought against this unilateral decision and asked the Congress for help. After practically one year of pending activity, Representative William S. Green (MA.) interceded with a House Resolution directing the Navy to end the prohibition on ham operations. The Navy eventually complied, and in November 1919, QST celebrated the return of amateur radio privilege on the air, closing his call with these words "Come on, fellows, and get into the air again.". The English amateurs resumed some months later, in 1920.

In the occupied Europe and until the begin of '20s, radio transmissions were prohibited. However, many undeground stations continued to transmit, and civilians, taking refuge in their cellar or in their attic, continued to listen at the radio too, like they did again during WW II. The only difference, these first "pirates" stations, unlicensed, were only know by their call, to name among the first belgian stations B7, D2, K2, P2, W2, etc. Anonymity prevailed.

The superheterodyne receiver

In 1918, Armstrong developed the superheterodyne receiver that incorporated the first local oscillator and intermediate frequency modules. The "superhet" as it is sometimes called qualifies a receiver able to function over a range or band of frequencies.

The word "heterodyne" means "beating", a technique producing a beating or heterodyne frequency by mixing two or more signals in a nonlinear device such as a vacuum tube, a transistor, or a diode mixer. The incoming frequency is converted to a fixed intermediate frequency (I.F.) where amplification and filtering are provided.

In a typical AM receiver, this IF is set on 455 Kc and usually on 10.7 Mc for FM VHF receivers. The "superhet" uses a local oscillator called a variable frequency oscillator (V.F.O.) to maintain a constant difference between its beating frequency and the received frequency to get a constant I.F.

The "Superhet" receiver

At left, an advertising published in 1929 starring Lee de Forest's invention, the Audion, better know as the vaccum tube triode. At right, a basic superheterodyne receiver which bloc diagram still applied to today receivers with some more modules. In the '20s it was not equipped yet with a RF stage (the front or first stage after the antenna) that improved much the receiving (sensitivity) of weak signals. But it already included a VFO..

In addition, in 1922 Armstrong created the superregenerative receiver, a simplified superheterodyne that improved the gain while simplifying the adjustment of the receiver. The "regen" as it was called was qualified as a receiver "unsurpassed in comparable simplicity, weak signal reception, inherent noise-limiting and AGC action and, freedom from overloading and spurious responses", nothing less. In fact the "regen" used an oscillating detector receiver that we will encounter in all V/UHF rigs in the '20s to the '50s, and that is still used today in children's walkie-talkies, and some receiver kits. The "regen" radios took the most of very few components. However, as parts became easier to obtain, the "superhet" replaced it in all radio activities. I will not learn you that the superheterodyne receiver is the most common receiver in use today.

Thanks to Armstrong's inventions, amateur radios will soon go into History.

Next chapter

The 1920s : The discovery of HF and DX communications

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