Wireless Heritage SIG 6th February 2014 - 100 Years of Radio

Our February meeting, ‘100 Years of Radio’ builds a narrative around some remarkable radios sourced from the private collections of Cambridge Wireless members. Each object marks a significant technology innovation or novel application of radio illustrating the technology changes that have taken place from 1914 to 2014 and their related social, political and economic impact.

We use this as a basis for establishing the shape of radio communication one hundred years from now. Given that many children born today will live to be 100 we are in effect talking about the next radio generation.

1914 is of course an arbitrary start date and it would be equally valid to begin ten or twenty years earlier but the First World War marks the moment when radio technology becomes strategically important particularly in aerial reconnaissance. As a taster here are just a few significant moments.

1907
The Great White Fleet

In 1914 politicians were keenly aware that the battle ‘for hearts and minds’ was a key part of the military engagement process. In December 1907 Theodore Roosevelt despatched the Great White Fleet, 16 battleships, six torpedo boat destroyers and 14,000 sailors and marines on a 45,000 mile tour of the world, an overt demonstration of US military maritime power and technology.The fleet was equipped with ship to shore telegraphy (Marconi equipment) and Lee de Forrest’s arc transmitter radio telephony equipment. Although unreliable, this was the first serious use of radio telephony in maritime communication and was used for speech and music broadcasts from the fleet – an early attempt at propaganda facilitated by radio technology.

1922
The Birth of Broadcasting- key enabling technologies

In practice it was 15 years before broadcasting became practical.  The British naturally consider they that they were first in the public service broadcasting race but so do the Americans and the French consider neither claim is credible.

Broadcasting would however not have been technically or commercially feasible without the valve technology developed by Fleming, the diode valve and the triode valve developed by the American Lee de Forest, an amplifier and oscillator in one handy package.

By 1920 two receiver architectures, direct conversion and the superhet were both understood in principle. The practical implementation of the superhet is usually credited to Edwin Armstrong and by the mid 1920’s in the US most receivers used this technique.

Adoption in UK and Europe was slower and crystal sets remained popular for a number of years partly due to their low cost and partly due to the fact that they needed no battery, working off the power from the incoming radio signal – a neat trick to replicate in a modern mobile phone.

However a basic economic truth was established that it is relatively easy to build the transmission network and relatively difficult to design user equipment that can be manufactured at a low enough cost and high enough performance to encourage the mass market adoption needed to produce a return on investment – a scale performance conundrum that still challenges the industry today.

1922
Hello to 2LO

The long wave transmitter designed by the Marconi Company starts broadcasting from an attic close to Bush House using the call sign 2LO. This magnificent machine is far too big and precious to make a trip to Cambridge but it will be on public display in the new Information Age gallery opening at the Science Museum in September 2014.

1924
The 'Beam System' and the Imperial Wireless Chain

First proposed in 1906, Marconi’s short wave ‘point to point’ radio system was adopted by Canada, Australia, South Africa and India and extended by Marconi to cover Argentina, Brazil, the USA and Japan.
The’ Imperial Wireless Chain’ was regarded as a threat to the Empire's cable interests.

In 1929 Cable and Wireless Ltd was formed to take over the investments, patents and licenses of Marconi's Wireless Telegraphy Company.

1936
VHF TV
The first VHF television broadcasts started from Alexandra Palace in London. This created a demand for television receivers which in turn created a demand for valves and tuned circuits capable of working at VHF with sufficient dynamic range and receive sensitivity.

1939-1945
The valve that won the war… the radio that won the war?
New high gain low capacitance EF50 glass valves made by NV Philips of Holland produced televisions that worked in areas with weak reception. This valve was subsequently used in radar products and two way radio systems including  the WS19 Pye dual band short wave/VHF radio set sometimes described as ‘the radio that won the war’.

1952
The Bakelite Bush 22
These war time advances provided the basis for a great leap forward in TV receiver technology in the immediate post war period. The Bakelite Bush 22 for example was introduced in 1952 and became a popular household item in time for the Queen’s coronation in June 1953.

1955
Colour TV test transmissions from Alexandra Palace
On the 10th October 1955 colour TV 405 line test transmissions started from Alexandra Palace and VHF FM broadcasting was introduced.

1957
The Transistor Radio – public safety and cold war radios
Sony released the world’s first low cost pocket transistor radio with an FM model introduced in 1958. In parallel the two way radio industry was transforming police, fire and ambulance services and less visibly, covert radio systems were being developed for Cold War response, surveillance and defence systems.

1957
The launch of Sputnik – the birth of the satellite era
The start of space communication

1962
Telstar
The first true telecoms satellite and forerunner of contemporary Inmarsat and Iridium satellite systems.

1971
Aloha Packet radio
The forerunner of Wi-Fi (1985) and Bluetooth contention protocols

1985
The first UK cellular networks

1991
GSM and the analogue to digital transition
The start of the rapid transition from analogue to digital radio.

Each of these innovations were significant but while it seems that much has changed much also remains the same.

Join us on February 6th for an all-embracing review of the past 100 years, some remarkable historic radio devices and a definitive view on what radio will look like in February 2114.