Abstract: A system and technique for detecting a recurring signal, for example, a synchronization pulse contained in an information signal stream modulated on a carrier signal, wherein the recurring signal has a known duration (.tau.) and a known period (T). The signal carrier is demodulated such that the recurring signal exhibits a certain characteristic amplitude variation over its duration .tau., and the demodulated signal carrier is sampled at intervals less than .tau. thereby obtaining signal samples exhibiting the amplitude variation of the recurring signal. The signal samples are applied to an input of a coincidence network including at least one delay circuit which provides a delay corresponding to the period T of the recurring signal to a passing signal sample, and input and output terminals of each delay circuit are coupled to different inputs of an associated coincidence gate circuit. Each coincidence gate circuit produces an output whenever its input signal samples coincide with one another.