Why do old TV’s always have that annoying high pitch noise when you turn them on?

Question

Why do old TV’s always have that annoying high pitch noise when you turn them on?

In: 3

Answer 1

Please don’t answer if you don’t know.

The picture is drawn on the phosphor screen of the tube by bending an electron beam with electromagnets. The beam is scanned across horizontally to make lines, and then much more slowly vertically, the scan position moves to the next line and the next line is scanned across the display, to make 60 fields per second.

The horizontal scan rate is 15.734kHz, a very high frequency or pitch within the hearing range of young listeners. The beam jumps from the right of the screen to the left 15000 times a second. The magnetic fields of electromagnets can cause internal vibrations that are radiated into the air: sound.