Amateur radio over the decades

A journey through the history of amateur radio — from Marconi’s pioneering years to today’s digital modes.

1900–1910

Following in the footsteps of Marconi and other pioneers, thousands of young experimenters built simple ‘spark’ transmitters and receivers to send Morse code messages in their neighbourhoods – which sometimes led to interference with commercial and military communications.

1910–1920

To resolve the issue of interference, a licensing system was introduced in 1912. Amateurs began to organise themselves into clubs, which formed the basis for today’s national associations in Australia (1910), Great Britain (1913) and the United States (1914). The World War led to the closure of amateur radio stations, but also to advances in radio technology, which were quickly adopted by the re-licensed amateurs to bridge greater distances.

The 1920s

Vacuum tubes (tubes) replaced spark gaps, reduced interference and increased the range. Amateurs make use of the remarkable properties of the ionosphere to enable global communication using relatively low transmission power and antennas that fit in a typical back garden. To retain access to the shortwave spectrum, amateurs had to withstand pressure from commercial and government interests; the IARU was founded precisely for this purpose. Despite the rise of AM radio, Morse code remained the predominant mode of operation for amateurs.

The 1930s

During the Great Depression, amateur radio developed into an affordable and rewarding leisure activity. It became possible to make contact with amateurs in 100 different countries, even though there were fewer countries back then than there are today. Television and research into the VHF spectrum kept leading technologists busy, whilst others built their own AM transmitters and voice communication became popular. Propaganda broadcasts dominated the shortwave bands and posed a new challenge to access to the amateur spectrum.

The 1940s

The Second World War led to the suspension of amateur radio in most countries. Once again, the technology was further developed to meet the demands of the war. After the war, surplus radio equipment was plentiful and inexpensive. This enabled amateurs to upgrade their stations and, for the first time, to use UHF and microwaves. A new mode of operation, radio teletype (RTTY), became audible as a result of the congestion on the amateur bands.

The 1950s

Television broadcasting posed a challenge for amateur radio operators, as it required new diplomatic and technical skills to eliminate ‘TVI’ interference affecting neighbours’ and families’ television sets. Nevertheless, it was a decade of rapid growth. Single-sideband (SSB) drastically increased efficiency and reduced the bandwidth required for voice communication. Mobile operation became popular. Towards the end of the decade, a peak in the sunspot cycle provided amateurs with the best ionospheric propagation ever recorded, either before or since. Following the launch of the first Sputnik, amateurs received the first signals from space. Heathkits – complete kits with step-by-step assembly instructions – captured a large share of the equipment market.

The 1960s

With the first satellites built by amateurs, amateur radio was officially ushered into the space age. Two-way amateur communication via the reflection of signals from the Moon (Earth-Moon-Earth or EME) was first achieved on 1296 MHz and later on 144 MHz. Back on Earth, SSB became the predominant HF voice mode. Separate HF transmitters and receivers gradually disappeared from amateur radio stations and were replaced by transceivers, in which many circuits were shared between the two functions. High-quality equipment from Japan began to appear in shacks around the world. Some countries began to issue licences for VHF and higher frequencies without requiring proficiency in Morse code.

The 1970s

Long-range satellites have made satellite communications an integral part of life for space-enthusiast amateurs. Bolstered by a large domestic market, Japanese manufacturers are becoming a global market force. VHF and UHF repeaters are enjoying increasing popularity and extending the range of mobile FM devices. In the mid-1970s, the ‘CB boom’ became the largest source of newly licensed radio amateurs, as more serious hobbyists fled the chaos of the Citizens Band. The decade ended with the important World Administrative Radio Conference (WARC-79), at which the IARU’s long-standing efforts led to the successful defence of the existing amateur radio bands and to new allocations at 10, 18 and 24 MHz.

The 1980s

Microprocessors became the driving force behind the rapid development of the digital aspect of amateur radio. Spurred on by the introduction of the AX.25 standard for digital data communication, ‘packet radio’ became a powerful new tool for message relaying. A further adaptation of a commercial standard, known in its amateur radio version as AMTOR, brought error-free data communication to the HF bands. The manned space programme found its way into shacks around the world when amateurs were able to communicate directly with an astronaut on board the Space Shuttle in Earth orbit – the first of many to follow on the International Space Station.

The nineties

Dramatic political events in Eastern Europe led to significant changes for radio amateurs there. Worldwide, the internet presents both a challenge and an opportunity: on the one hand, it competes for the time and attention of technology-savvy young people; on the other, it offers an unprecedented medium for the exchange of information. The digital revolution further drove the development of amateur radio; there was hardly an amateur radio shack without at least one personal computer integrated into the station. PSK31, a digital mode developed specifically for amateur radio and not based on any commercial standard, offered performance comparable to CW with weak signals and narrow bandwidth.

The 2000s

The introduction of WSJT, a suite of open-source programmes for digital communication with weak signals in amateur radio, sparked a wave of propagation observations and studies utilising techniques from radio astronomy. Digital voice became popular. Software-defined radios (SDRs) offered possibilities that had been unimaginable just a few years earlier, and at prices that amateurs could afford. At the 2007 World Radiocommunication Conference (WRC-07), an amateur radio frequency (LF) of 136 kHz was allocated for the first time. At the next two WRCs, in 2012 and 2015, new amateur bands of 472 kHz and 5 MHz respectively were allocated. At WRC-19, a drastic improvement to the 50 MHz band for amateurs in Region 1 was agreed, thereby achieving a degree of global harmonisation in this interesting part of the spectrum. Amateur radio pioneers from a century ago would be amazed at what amateurs can do today – and there is even more to come!  

Source

https://www.iaru-r1.org/amateur-radio/amateur-radio-through-the-decades/ (31 December 2019)