Abstract: A method and means is described for a concealed structure locating and surveying exciter apparatus, and more particularly, to a portable device which couples, either by direct or indirect connection, high frequency alternating current energy into a more conductive structure which is usually obscured in a less conductive covert medium. The preferred embodiment provides two different frequency high stability sources of first oscillations the outputs of which are alternately switched or gated by a very low frequency source of second oscillations. The alternating first oscillations are combined in a summing amplifier and caused to drive an output coupling means. The amplified outout is further modulated, usually at an audio frequency rate, by a low frequency source of third oscillations.

Abstract: My new invention describes a method and means for a receptor or translator apparatus suited for positionally spotting and tracing subjacently concealed conductive structures through the detection of a cooperative separately induced pair of radio frequency signals modulated by a constant amplitude radio frequency tone. The pair of radio frequency signals are predeterminately caused to occur either simultaneously or in a sequentially ordered alternative form. The receptor further includes a pair of inducer means in different spatial displacements with each inducer means being operative to be singularly responsive to but one of the pair of radio frequencies emanating from the concealed structure. The independent inducer signals are subsequently amplified and independently demodulated so as to result in two separate audio frequency tones the volume of which are individually proportional to the radio frequency signal level picked up by either of the pair of inducers.

Abstract: My invention relates to improved method and means for a portable concealed structure locating and surveying exciter apparatus, and more particularly, to a portable device which couples by indirect connection alternating current energy into a structure which is usually obscured in a covert medium. A high stability source of first oscillations is provided which is undisturbed by perturbations in the degree of coupling between the concealed structure and the exciter, together with an adjustment, which is operable by a user of average skill, for maximizing the induction field when the apparatus is in the immediate presence of a large conductive structure which can otherwise affect the resonant efficiency of the inducer, thereby permitting the most effective use of an associated electromagnetic field detector apparatus of high selectivity.

Abstract: My invention relates to improved method and means for a portable concealed structure locating and surveying apparatus, and more particularly, to a portable device which provides separate operating conditions to best initially locate, then subsequently trace or survey a hidden structure or extended object with a minimum of operator interpretive skill. My invention includes an inductive exciter which couples by indirect connection alternating current energy into the structure which isusually obscured in a covert medium. My invention includes also a portable translator which is, in the locating or spotting mode of operation, operating with gain modulation at a slow periodic rate to enable the use of the full, noise limited, gain capablity of the electronic amplification means. I have further conceived a novel way that the noise thus resulting is used as an aid in the initial locating of the indeterminate structure lay.