Illustrated here is the measurement system that was used to test the radiated emissions from 0.15 to 30 MHz. The system is based on CISPR25. The frequency-noise level graph on the right shows the initial test results of the DC/DC converter board. Noise floor is represented in black, and the CISPR25 Class 5 specification is represented by the horizontal purple lines. The blue spectrum is the initial noise measured. Like the previous conducted test, the noise interval spikes are at 400 kHz, which is the same as the switching frequency of the DC/DC converter. The noise level measured is not in compliance with CISPR25 requirements.