Traditional receiver — 15 ms scan
Based on Figure A-5 · adjustable scan time.
Measured peakPulse envelopeCE102 115 V limit
EMC — Reference Tool
MIL-STD-461G receiver examples
Four adjustable plots based on Appendix A, Figures A-5 through A-8. A-6 through A-8 default to the timings stated in the appendix; A-5's scan-time range has been extended down to 15 ms so it can be compared directly against the FFT dwell examples. Use the sliders to compare other timings. The plots compare a traditional scanning receiver with an FFT receiver for the standard's example signal: one 10 µs, 0.1 V pulse every second.
What the four figures demonstrate
A 1 Hz pulse train has a one-second repetition period. A traditional receiver moves its narrow bandpass through the spectrum, so individual pulses are caught only at the frequencies inside the bandpass when each pulse occurs. A longer scan catches the pulse at many more frequency positions. An FFT receiver observes a complete frequency block at once: if its time record catches the pulse, it produces the continuous spectral profile; if not, the whole acquisition can miss it.
For 10 kHz to 150 kHz, MIL-STD-461G Table II specifies a 1 kHz, 6 dB resolution bandwidth, a 15 ms dwell for a stepped-tuned receiver and a 1 s dwell per FFT measurement bandwidth. The longer FFT record is deliberate: the Appendix example shows that 15 ms gives only a 1.5% chance of intercepting a pulse that occurs once per second.
Pintercept ≈ min(1, tdwell / Tpulse)
Reference signal
Defaults reproduce the values stated in MIL-STD-461G Appendix A.For FFT records shorter than one pulse period, select a captured or missed acquisition above. The probability updates with dwell time. Records covering a full period always capture a pulse in this idealised model; longer dwell does not increase the displayed peak.
Traditional receiver — 300 s scan
Based on Figure A-6 · adjustable scan time.
Measured peakPulse envelopeCE102 115 V limit
FFT receiver — 15 ms dwell
Based on Figure A-7 · adjustable dwell time.
Measured peakPulse envelopeCE102 115 V limit
FFT receiver — 1 s dwell
Based on Figure A-8 · adjustable dwell time.
Measured peakPulse envelopeCE102 115 V limit
These are original, illustrative recreations of the behaviour described by MIL-STD-461G Appendix A, not copied standard figures and not simulated receiver calibration data. The CE102 115 V limit is included for orientation. Use the controlled standard and the verified settings of the actual measurement receiver for formal work.