Trevor Wadley

[1] He then went to Howard College (now the University of KwaZulu-Natal), where he studied under Hugh Clark and Eric Phillips, after which he completed his Thesis (D.Sc.)

[2] GR Bozzoli noted in is book Forging Ahead – South Africa’s Pioneering Engineers that Wadley "would very occasionally take out a small pocket notebook and write a word or two in it using a blunt, stubby pencil.

Wadley and other colleagues including Jules Fejer, the Hungarian-born mathematician, were trained on the British RADAR project.

[1] In 1946, Wadley was employed as a designer of radio equipment and instrumentation in a special division of the Telecommunications Research Laboratory (TRL), created at the behest of Prime Minister Jan Smuts and located at the electrical engineering department of the University of the Witwatersrand (under Basil Schonland).

[1][3] In 1948, Wadley started working on an urgent project for the South African Chamber of Mines to provide a means of radio communication underground for rescue purposes.

The Wadley Loop was first used in the Racal RA-17 a 1950s top-of-the-range British military short wave receiver and later in the South African made, commercially available "Barlow-Wadley XCR-30" radio.

[1][6] A Wadley receiver (circa 1952) is on display at the South African Institute of Electrical Engineers historical collection in Observatory, Johannesburg.

Colonel Harry A. Baumann (Rhodes Scholar, engineer and Land Surveyor) of the South African Trigonometrical Survey had already come up with the invention and Wadley developed it further.

[1][2][6][10] One of the first test of the tellurometer involved a measurement of the distance between Brixton Hill in Western Johannesburg and Fort Klapperkop in Pretoria, this being the most accurately known survey baseline in South Africa at the time.

Subsequent sales of the device earned more than R300 million (in 1960's terms) in foreign revenue for South Africa.