Your CRT monitor needs a degauss

[--Pete]

Hi,

Took about 2-seconds once I found it in the monitor menu. What does a degauss do anyhow? I never really gave it much thought.

Oh, no! You interjected 'serious' in a fun thread. Ah, well, the damage has been done.

Basically, the electron beams that paint the pictures on the CRT screen are guided by electromagnetic coils. It can happen that parts of the monitor will pick up a (semi)permanent magnetic charge. If that happens, then the beam steering will be off, leading to fuzzy pictures and even distortion in extreme situations (like at a particle accelerator where there are *big* magnets). To remove these magnetic charges, an oscillating current is passed through one or more electric coils, causing an oscillating magnetic field which 'scrambles' the magnetic charges. The same principle is used for bulk erasing of magnetic tapes.

Modern CRTs are shielded much better and are made of much better materials so that they seldom if ever need degaussing. But if you want to see some of the effects of stray electromagnetic fields on your monitor, just put a desktop fan with a plastic case next to it. If you're lucky, your monitor will look like it's on an acid trip;)

--Pete