Sometime electronic devices are disturbed by unknown R.F. noises. To solve this problem, it is need to restudy the present technology for R.F. noises as following subjects ; continuous oscillation and damped oscillation. disturbance for receivers and electronic devices. CISPR measuring method for damped oscillation, and mechanism of R.F. noises induced in distributed constant circuit, merit and demerit of XY condenser, once disturbance for electronic device during one years and ete.
