In a wide band receiver, a pulse signal is directed through a plurality of narrow band channels. The pulse input is a short duration pulse of several cycles of the signal. The energy content in each of the narrow band channels is measured and compared to adjacent channels. During the steady state time, when the pulse signal is neither rising or falling, the energy differences between a narrow band channel being at the location of the incoming signal frequency and its adjacent channels would be maximum and exceed established thresholds. A comparison is then made with these established thresholds to produce logic signals demonstrating that the incoming is in an indicated narrow band channel. Where the signal is between two channels and in the crossover region, then the logic signals produced during the steady state pulse time would be indicative of substantially equal energy in the two narrow band channels having portions in the crossover region while the energy differences between each of those narrow band channels sharing the crossover region with their respective adjacent channels would be greater than the CCR levels. Logic signals indicative of these energy relationships are then processed to produce the signal indicative that the incoming signal is in the crossover region. The system operates to produce logic signals only during the steady state time of the pulse and is free of splatter which would otherwise prevent a clear and unambiguous indication of frequency.