Captain H.J. Round

H.J. Round:- the little known genius who added much to thermionic valve / vacuum tube development and made significant developments to ASDIC radio direction finding and other areas of wireless technology

Captain Henry Round is a little known genius in the field radio early radio development. As a result of his efforts H.J. Round had a great impact on British history. His developments in radio direction finding noticed the movement of the German navy which he reported and this resulted in the Battle of Jutland, the largest naval battle of the First World War.

In addition to this H.J. Round made significant contributions to the development of the thermionic valve or tube, and he also worked successfully on the development of ASDIC.

As for his character, Captain H.J. Round was something of an individual and an extrovert. He was also short in stature, and his looks were said to be similar to those of Winston Churchill, even down to a cigar. He also had a dislike for unnecessary protocol, preferring to get to the point as soon as possible.

Captain H.J. Round
Captain H J Round
Image courtesy Marconi plc

Round's early years

Henry Joseph Round was the eldest child of Joseph and Gertrude Round and was born on 2nd June 1881. He spent his early years in the small town of Kingswinford which is in Staffordshire, England.

Henry Round's early education took place at Cheltenham Grammar School. Later he furthered his education at the Royal College of Science and here he gained first class honours degree.

H J Round's first employment

H.J. Round commenced his professional life when he joined the Marconi Company in 1902. The company was very newly formed and was at the forefront of "wireless" technology having made the first transatlantic radio transmission the previous year. However the investment in achieving these new milestones was huge and the returns at this time were relatively small. Despite the shortage of cash, H.J. Round was sent to the USA. Here his office junior was a man named David Sarnoff - he alter became the Chairman of RCA.

While in the USA, Round experimented with a variety of different aspects of radio technology. From early 1903 until 1904 he focussed on dust cored tuning inductors as the concept of tuning a signal was still in its infancy, and methods of satisfactorily tuning receivers and transmitters was needed.

While H.J. Round's main focus was on studying tuning, he was also able to spend time performing some experiments with transmission paths over land and sea at different times of the day. He also spent time investigating direction finding for which he used a frame antenna. What he learned from these experiments would prove very useful in his later work.

In further work that H.J. Round undertook, he made some ground-breaking discoveries, one of which was over fifty years ahead of its time. In 1906 H. H. Dunwoody had discovered the crystal detector which was a very important rival to Fleming's diode valve. (Interestingly the patent for the diode valve was owned by Marconi as Fleming was a consultant to the company). Round performed a number of experiments on the crystal detector using a of materials. He also applied a direct current to them and noticed that some actually emitted light. H.J. Round reported this in the 9th February 1907 edition of Electrical World. This is the first known report of the effect of the light emitting diode.

To the Editors of Electrical World:
  Sirs:- During an investigation of the unsymmetrical passage of current through a contact of carborundum and other substances a curious phenomenon was noted. On applying a potential of 10 volts between two points on a crystal of carborundum, the crystal gave out a yellowish light. Only one or two specimens could be found which gave a bright glow on such a low voltage, but with 11 volts a large number could be found to glow. In some crystals only the edges gave the light and others gave instead a yellow light, green orange or blue. In all cases tested the glow appears to come from the negative pole, a bright blue-green spark appearing at the positive pole. In a single crystal, if contact is made near the center with the negative pole, and the positive pole is put in contact at any other place, only one section of the crystal will glow and that the same section wherever the positive pole is placed.


H. J. Round

Unfortunately Round was well ahead of his time and it took until the 1960s before it was fully exploited.

Job changes

The cash shortages experienced by the Marconi company forced some drastic measures, and Round had to be discharged from the company. He looked for new employment, and although he was turned down by Edison, he did manage to take up a post with the New York Telephone Laboratories.

After a short period the Marconi finances recovered and H.J. Round was able to re-join to the company and return to England. Now Round became investigated solutions to the problems of valve amplification. This work soon paid dividends and in 1913 and the following year Round patented a number of ideas for valve improvements including that of an indirectly heated cathode. This was a major step forward and it paved the way for enabling valves to be used far more widely. Also during this time he patented his auto-heterodyne (autodyne) receiver and developed the first use of automatic grid bias.

H.J. Round's Autodyne Receiver
H.J. Round's Autodyne Receiver

First World War

The First World War broke out in 1914. The military authorities realised the benefits that could be reaped from wireless communications, and accordingly Round was seconded to Military Intelligence with the rank of Captain.

Calling on his previous experience with direction finding, Round set up a chain of direction finding stations along the Western Front. These stations proved to be so successful that he was instructed to set up a second chain of stations in England. In May 1916 they were monitoring transmissions from the German Navy that had been at anchor at Wilhelmshaven. On 30th May they reported a 1.5 degree change in the direction of the signals being picked up from the German fleet along with an increase in activity. The information was reported to the Admiralty who reasoned the German fleet had put to sea. Accordingly the Admiralty ordered the British Fleet to put to sea to intercept the Germans, and the following day the Battle of Jutland was fought. It was the largest sea battle of all time. In it the British fleet lost seven ships and about 7000 men, whilst the Germans only lost three ships and around 2500 men. While the British suffered greater losses, it meant that the German fleet did not sail. After the war it was revealed that it was as a result of the endeavours of Captain H.J. Round that the Battle had taken place.

Captain H.J. Round made other contributions to the war effort, designing the first telephony transmitters and receivers for airborne use. For all his services during the war, Round was awarded the Military Cross.

Round returns to civilian life

With the cessation of hostilities, H.J. Round returned to more peaceful and commercially profitable activities working for the Marconi Company. Initially his activities were devoted towards the development of improved thermionic valve or tube activities. He developed some new high power valves or tubes (types MT1 and MT2) and alongside this he developed some transmitters capable of delivering around 20 kW. Then in March 1919 he oversaw the installation of a large telephony wireless station at Ballybunion in Ireland.

With the transmitting station complete, H.J. Round next developed some more transmitters, but this time for range testing. The radio transmitters were located at the Marconi works in Chelmsford, and in order to gain an idea of the ranges being achieved, listeners were invited to send in reports on the transmissions. In order to attract listeners, the transmissions were modulated with music - a revolutionary idea for the time. The number of listeners grew and many reports were received by those who had enjoyed the radio transmissions. As a result the idea of radio broadcasting dawned in the United kingdom, and a regular wireless telephony news service was inaugurated on 23rd February 1920. Three and a half months later on 15th June 1920, the famous Australian soprano Dame Nellie Melba took part in a broadcast concert organised by the Daily Mail. This radio broadcast created a significant amount of public interest and many people listened to it.

These early British radio broadcasts were not without their problems. They caused interference to what were thought to be "more serious" uses for wireless and they were stopped. However, two years later another set of broadcasts was inaugurated. The transmission site for these was at Writtle just outside Chelmsford. In line with all stations of the day a call sign was assigned to the station and for this one it was 2MT (Two Emma Tock). It took to the air using a transmitter that had been designed by H.J. Round.

The success of this station lead to the establishment of another station at Marconi House in the Strand. With the call sign 2LO this station was taken over by the BBC at its formation in 1922. From this it can be seen that H.J. Round naturally played a very significant role in the foundation of broadcasting, providing much of the technical expertise and drive to ensure that it succeeded.

Amidst all of this work, H.J. Round was still working on a number of other projects. One of the major jobs was the conversion of the Marconi wireless station at Caenarvon, Wales from a spark transmitter to a valve or tube transmitter. This radio transmitter used a total of 56 of Round's MT2 valves or tubes with a 10 kV supply. The station was naturally very powerful, and as a result on 19th November 1921, signals from it were heard in Australia.

Career moves for Round

Round was appointed to the post of Chief Engineer at Marconi Research in 1921, and he remained with the company until 1931 producing a huge amount of work. During this time he undertook a wide variety of different projects including the design d development of radio transmitters and receivers, gramophone recording systems, and he even developed a public address system that was used to relay the speech by King George V of England at the Wembley Exhibition.

Despite all his successes, Round decided to set up his own private consultancy in 1931. Although he still worked closely with the Marconi Company on many occasions it gave him more flexibility to undertake the work he wanted to do. However shortly after the outbreak of the Second World War he was commissioned to work for the UK Admiralty (the department that ran the British Navy) on ASDIC. The letters ASDIC, stand for AntiSubmarine Detection Investigation Committee, and the system is known as Sonar today. After the war he undertook more work for the Marconi Company, working primarily on echo sounding, a field in which he was considered an expert.

Personal Life

H.J. Round married Olive Wright Evans in 1911 and they had seven children: two sons and five daughters. Sadly his eldest son John who was a Spitfire pilot in the Second World War was killed in action. Round outlived Olive and was remarried in 1960 to Evelyn Bays. Round himself died in August 1966 in a nursing home in Bognor Regis after a short illness.

Looking back

H.J. Round achieved a phenomenal amount in his life. He was known for his huge work output and the number of development "firsts" to his name. He revolutionised the design of radio receivers of the day. He developed new valves and moved forwards thermionic technology. In addition to this he played a significant role in the technology used in two world wars. He also had the distinction of being the first person to note the effect used today in light emitting diodes.

Round was awarded two main honours. In the First World War there was the Military Cross for his efforts mainly on direction finding and then in 1951 he was awarded the coveted Armstrong Medal by the Radio Club of America. Despite these two awards and the huge impact of many of his developments, the name of Captain H.J. Round is not widely known and he is very much an unknown genius.

H J Round facts

A summary of some of the chief facts about Henry Joseph Round:

Key H J Round Facts
Fact Details
Birth date 2 June 1881
Birth place Kingswinford, Staffordshire, England
Parents Joseph and Gertrude Round
Death 17 August 1966, Bognor Regis, England
Education Cheltenham Grammar School then Royal College of Science (1st class honours degree)
First employment Joined the Marconi Company in 1902
Main contributions Improvements in thermionic valve (vacuum tube) technology, development of sonar
Other notable work First to observe and publish the light emitting diode effect (1907)
Patents 117 patents held

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