Nikola Tesla Books
IN SEARCH OF NIKOLA TESLA I remembered once listening to some conversations on communication during a nuclear war. If it ever came to pass that a large number of hydrogen bombs were detonated, then conventional radio communications would become impossible because of extensive interference and ionization from the nuclear explosions. The problem then was for a country to maintain contact with its missile-carrying nuclear submarines deep under the ocean. How could this be done? One suggestion was to make use of radio waves at very low frequency â just a few cycles per second. Low frequency radiation is fairly impervious to interference and would penetrate under the sea to submerged submarines. Now, low frequencies mean long wavelengths. A United States proposal called 'Project Sanguine' had come up with the design for an antenna a million metres long which would be looped for convenience over an area of a billion square metres. Possibly a Russian version of 'Project Sanguine' already existed and was sending out test transmissions. However, unless some curious new modulation effects were being investigated, the signals would be in the low-frequency range and nowhere near the millions of cycles per second which were being picked up by angry short wave listeners. Another possibility which occurred to me was âover-the-horizon radar' which I knew was being investigated in several countries. Conventional radar is used to plot the path of incoming aircraft or hostile missiles but is limited in range since the beam cannot 'bend' over the horizon. If the target is too far away then it is effectively 'over-the-horizon' and as invisible to conventional radar as it would be to a man with a telescope. One solution is to extend the 'line of sight' of the radar by placing the set in an aeroplane and flying as high as possible. The higher the radar set then the further away it can spot an intruder. An alternative approach to airborne radar is to 'bounce' the signals over the horizon. The experimental testing of such an âover-the-horizon radar' station seemed another plausible explanation for the Russian signals and one which the experts in radio communication seemed willing to accept. By the end of the morning I felt that I had accomplished a great deal. I now knew that the newspaper stories of radio interference were based on fact, although it was not yet clear what sort of experiments were responsible for the signals. 35
