Abstract: Apparatus for lowering the noise threshold at which FM and other angle modulated signals may be demodulated is described wherein an oscillating limiter provided by an amplitude limiter having a bandpass filter in regenerative feedback relationship therewith is connected ahead of the demodulator. The bandpass filter is made tunable in response to a steering signal developed by processing the frequency proportional signal at the output of the demodulator to attenuate high frequency components thereof which are outside the baseband of the signals and adjusting the amplitude of the signal so that the center frequency of the bandpass filter is caused to substantially match the frequency of the frequency modulated signal.