Coil Coupled Operation Metal Detector
Rev. Thomas Scaraborough
A Coil Coupled Operation Metal Detector made from readily obtainable components and using an ordinary
medium receiver as a detector.
The metal detector shown here may well represent a new genre. At any rate, after some exposure, it
is regarded as such by those who have seen it. It is based on a standard transformer coupled oscillator
(TCO) - hence the name Coil Coupled Operation (CCO) Metal Detector. Although requiring a BFO (in this
case provided by a Medium Wave radio), it differs from a typical BFO detector in that its performance
far outstrips that of BFO. Also, unlike BFO, it is dependent on the balance of two coils to boost
sensitivity. It also differs from IB, in that its Rx section is an active, rather than passive,
component of the oscillator. Further, unlike IB, the design does not require critical placement of the
coils. As with both BFO and IB, the design provides discrimination. Experiments with different embodiments
of the idea have shown that it has the potential to match the best of IB. Happy hunting!