The most powerful instrument is the one that is used.
     If that motto is true, then Vaino Ronka invented the most powerful electrical geophysical instrument. More of his VLF electromagnetic survey instruments have been used around the world than any other electrical prospecting tool.
     Yet the VLF-EM was only one of Vaino's many successful geophysical instrument designs. In the 1960s, a list was published of all the mines discovered in Canada during the previous 10 years. Out of 15 mines on the list, about 75 percent were discovered by Ronka-designed instruments.
     Vaino Ronka began his work in geophysics as a research assistant on a new fixed-wing, quadrature-phase, airborne electromagnetic system at the Geological Survey of Finland. When the Hunting Group in Toronto purchased the system in 1953, Vaino moved to Toronto to help design a two-frequency version of it for commercial use. Nine months later, in September 1954, it was in operation, and won the Blue Ribbon Mining Award.
     In July 1954, Vaino applied for a patent for an in-phase and quadrature towed bird helicopter EM system. When the system went into operation in 1955, it included a built-in scintillation counter, also of his design, and was one of the first transistorized commercial instruments of any kind. It again won the Blue Ribbon Award.
     About this time, Vaino began to think of an improved horizontal-loop ground EM system. When it appeared in the field in 1957, it set the standard for ground-based EM systems.
     At the end of 1958, Vaino started independent design services for geophysical instruments. One of the projects was instrumentation for Hunting's "hydrosonde." He also designed Hunting's FS-I and FS2 portable seismographs and the popular Hunting time-domain IP receiver.
     In 1962, Vaino founded Geonics Ltd in Toronto with partner Alex Herz. While they were in the field near Bancroft, Ontario, doing tests on the EM-IS ground EM instrument, they started picking up Morse code from VLF radio transmitters used to communicate with submarines. If these signals could be picked up as noise, Vaino figured that they could also be used as signal. Thus instead of tediously erecting a heavy, cumbersome, local transmitting station for every small piece of survey line, explorationists might simply tune in to distant VLF radio stations and use those fields to detect mineral deposits. This was the basis of his EM-16 VLF-EM receiver, which was first sold in 1965.
     Although some geophysicists vigorously opposed the instrument on the basis that it used frequencies higher than the normal EM range and thus would pick up many poor conductors, the advantages of the instrument were obvious. It was about the size and weight of a transistor radio, and was the least expensive of all useful electrical geophysical prospecting tools. A prospector could carry a pick in one hand and an EM-16 in the other, and many did. The EM-16 became the best-selling electrical geophysical instrument of all time, and is still selling briskly today, under the same model name, 25 years later. Its tendency to detect weaker conductors has recently been put to very good advantage, as gold mineralization is often associated with poorly conducting
     fault zones.

     Vaino went on to design the EM-18 as an airborne VLF instrument. Another airborne survey system, the EM-30 of Hudson Bay Mining, was also based on Vaino's patent and ideas.
     In 1969, Vaino had a heart attack. It was a warning to slow down a little. He sold Geonics, and in 1973 he escaped west to Vancouver. There he designed the successful "Totem'' VLF-EM system which was further developed by Alex Herz.
     I had the great pleasure of spending considerable time in India in the late 1970s with Vaino on a consulting project for the United Nations. Some of the most enjoyable and stimulating discussions of my life were spent with Vaino destroying table napkins
     in Hyderabad restaurants with designs of futuristic EM and IP systems.
     As a professional, he was indignant at those who, through shoddy research or ulterior motives, tried to foist a "black box" airborne gravimeter on the Toronto geophysical community in 1960. When he built his own "hokumeter" with a simple galvanometer to measure electrostatic potential between the plane and the outside air and exactly replicated the data of the wonderful new airborne gravimeter, that particular black box rapidly faded into history. It is a measure of his very quiet, humble, but somewhat mischievous character that he finds much more pleasure recalling his design of the "hokumeter" than all of his many other inventions combined.
     It is particularly fitting for SEG to recognize Vaino's major contributions to the geophysical profession with the Fessenden Award. Reginald Fessenden's original patent in 1917 was for a Method and Apparatus for Locating Orebodies. Vaino Ronka's inventions have located many orebodies. The most powerful geophysical devices are often beautiful in their simplicity. They get used; they find mines, and they find them cost-effectively.

     William H. Pelton