Book Review: Point to Point: A History of Telecommunications During the Radio Years
David Harris reviews a volume that looks back to a time when short wave technology was exploited for international communications - after the use of VLF long-distance communications and before the arrival of the cable.
Author: David Harris
If you want to make an international telephone call today, it is simply a matter of looking up the dialling code, ringing the number and making the call. Yet, between the 1920s and 1960s (and until the 1980s for some remote places) international calls were made on shortwave radio circuits.
These circuits linked the UK to the rest of the world. Point to Point is a fascinating account of the history of point-to-point communications, written by a man who began his working life as a technician apprentice with the Post Office at Dorchester International Radio station, which first opened in 1927.
In some ways, this book is a general history of radio and is nowhere near as esoteric as the title might suggest. The writer knows his subject and had access to an impressive collection of archives and resources. He writes with clarity and never lapses into technical jargon, despite his impressive technical background.
The volume begins with a brief history of telegraphy over wires and cables, before looking at the early history of radio and the pivotal role of Guglielmo Marconi (1874 to 1937). One thing that is stressed throughout the book is the constant evolution of communications: Aerial designs, valves and tuning were all improved from the original equipment first used by Marconi.
In the 1920s, short wave radio began to be used for international voice communications. Previously, very low-frequency transmitters were used, utilising massive RF power and huge antennas. Marconi pioneered highly directional beam antennas, which meant that transmissions could be targeted at certain countries. At the time there was but little understanding of propagation and of the role of sunspot activity. In 1927, the first public trans-Atlantic radio telephone service was established at a cost of £15 for a 3-minute call. This was the equivalent of a month’s pay for a working person.
Gradually, throughout the 1920s and 1930s, improvements were made both to the technology and in the understanding of propagation conditions. Single side band (SSB) was introduced, along with crystal-controlled transmitters and highly directional aerials known as Multiple Unit Steerable Arrays (MUSA).
The author also explains the concept of diversity receivers, where two linked receivers in different locations are used to counteract the fading of radio signals. In 1926, the first radio facsimile service began, allowing newspapers to send photographs by radio around the world.
There is a brief chapter on radio during the Second World War when the government took control of all public communications. Some cable services were cut by enemy action, which put more pressure on shortwave radio links. After the war, there was a strong demand for international SW services for both voice and data communications. Very low frequency (VLF) services ended, apart from those used by the Royal Navy to communicate with submarines. In 1930, there were only 4,500 international calls made from the UK using international radio links. By 1956, this had risen to 100,000 calls a year.
The author also examines the international regulation of the radio spectrum and examines how frequency allocations were agreed to enable different services such as Aeronautical, Maritime, Broadcast, Amateur and Fixed service to have their own designated radio bands. It was not until 1956 that the first trans-Atlantic telephone cable was laid. Although telegrams could be sent (in Morse code) across the Atlantic by cable in the mid-19th century, the technology to amplify speech over cable was slow to develop. As more and more countries became connected by telephone cable, the demand for HF radio links slowly declined. In 1962, the communications satellite Telstar was launched and the writing was well and truly on the wall for SW point-to-point services. However, in some cases, HF was retained as a backup for when cable or satellite links were out of use for maintenance purposes.
This book provides a detailed study of the numerous transmitting and receiving stations maintained by the Post Office and shows how they were gradually phased out as demand declined. The last international point-to-point radio telephone link to close was the service between the UK and the Falkland Islands, which ended in 1983 when satellite communications were installed after the Falkland War. The final HF telex link to close was a diplomatic circuit between the UK and Moscow in 1990. The last remaining SW telephone service was Portishead Radio, which provided ship to shore communications until 2000 when satellite services to ships became widely available.
In 2003, radio station GBR, which broadcast VLF traffic to submarines on 16kHz ceased, bringing an end to VLF communications which had first been started by Marconi over 100 years previously. Some VLF services continue in the shape of a time signal station (GSF) which transmits on 60kHz.
The book concludes with the author’s reminiscences of his work at Post Office radio stations. It is a fascinating account of a life, which was probably not unlike working on a ship or in any ‘closed’ community.
The book has an impressive 15 pages of tables, which list all international radio services and ground stations referred to. There is also a very comprehensive bibliography, some diagrams explaining certain transmission modes and a full index.
I feel that this book will appeal to almost anyone with an interest in radio, as it provides such a clear overview of the history of telecommunications. It is also exceptional value for money.
I look forward to reading more from Paul Hawkins.