Abstract: A system for receiving information encoded in a train of pulse position modulated signals and then decoding the pulse train to produce amplitude modulated signals representing the original information includes a circuit for detecting the beginnings of successive PPM signals, a one-shot multivibrator responsive to the beginnings of the PPM signals for producing pulse width signals whose duration varies in accordance with the received intelligence, and an R-C low pass output circuit coupled to the output of the multivibrator to produce amplitude modulated output voltage waves. The R-C circuit has a time constant substantially greater than the unmodulated period between PPM pulses, and produces a rising voltage that spans the time duration of an associated high voltage level square pulse and whose decaying voltage level varies in amplitude in accordance with the maximum voltage attained at the output of the R-C integrator by the trailing edge of the associated high voltage level pulse.