This PCB is a usefull tool to make the Smartphone-Radiation visible. the LED lights up, if something is sent on a 2GHz frequency. If it lights very bright, there is a strong Radiation. if it only lights a litlebit or blinks, there is not so much of Radiation.U1 = LM258DQ1 = BC848D1 = LED Red 1206C1 = 1uF 1206C2 = 1uF 1206C3 = 100uf 1206R1 = 100k 1206R2 = 220k 1206R3 = 1.6M - 2.5M 1206 (Sensitivity of your Detector)R4 = 1k 1206