What frequency is the high pitch buzz from a CRT display?
The high pitched whistle that you can hear when the tv is switched on is at 15.625kHz . This is the frequency of the line scan (left to right of the screen) timebase. This occors in all CRT screens, though some are louder than others. This is nicely inside the human hearing range, though some older people can’t hear it. LCD won’t have this noise as it is purely electonic switching of the individual pixels on the screen rather than magnetically deflecting 3 electron beams. If your migranes have gone, great! The TV could have caused them with the constant whistling noise.
