This circuit was obtained from Dutch documentation from 1967. It uses transistors of the time which can be the BFY50 and 51 for the output and the BC series for the others.
This useful inductance bridge was found in a Radio Electronics from September 1963. The...
This circuit is a handset receiver that picks up the signal emitted by a coil under the rug or...
This circuit found in the October 1975 issue of Radio Electronics magazine uses an integrated...