Trevor Wadley

Trevor Lloyd Wadley (1920 – 21 May 1981) was a South African electrical engineer, best known for his development of the Wadley Loop circuit for greater stability in communications receivers and the Tellurometer, a land surveying device.

Life and career Wadley was born in 1920 in Durban, South Africa. His father was the Mayor of Durban and Trevor was one of 10 children. He attended Durban High School where he excelled in mathematics and science but was uninterested in any sport. The exception was one year when he entered the annual cross-country athletics event and predicted that he would win in record time and his record would stand for 15 years. He went on to do exactly as he had predicted. His training method involved calculating the time he needed to run each section of the course and then training himself to run at the required pace for each section.

When the system was demonstrated in England before a group including the British Prime Minister, Harold Macmillan, it showed that a line on the Salisbury Plain which had been used as the baseline for British surveying had been incorrectly calculated by 1.5 meters. Subsequent sales of the device earned more than R300 million (in 1960's terms) in foreign revenue for South Africa.

Ionosonde

At the CSIR he developed a local version of the device called an ionosonde for measuring the Earth's ionosphere; the original device was developed by Breit and Tuve in 1925. It is a specialised form of a radar detector used to measure the height of the ionised layers of air between 50 and 600 kilometers. This information gives insight into what is occurring during an ionospheric storm. The ionosonde was used to provide a transmission frequency prediction service to the SABC, the South African Postal Service (SAPO) and South African Military.