Tedium - Distorting The Electron Gun 🧲

Today in Tedium: As you read this, you are likely in a room surrounded by screens. We all are. They are everywhere, in giant, slab-like form; in moderate, tablet-like form; and in handheld sizes that fit in your pocket. But one nice thing about these screens is that they have continually improved in many ways, and as a result, you no longer need to do something that people with screens had to do back in the day: degaussing. This was a fact-of-life thing with CRT monitors, and now, we don’t even have to think about it anymore. If you haven’t used a CRT monitor in, oh, 20 years, you probably forgot about it entirely. Today’s Tedium discusses why we needed to do it … and why, in its own way, degaussing is friggin’ awesome. — Ernie @ Tedium

Today’s Tedium is sponsored by Morning Brew, an awesome newsletter you should check out. More from them shortly.

(Zach Vessels/Unsplash)

So what’s the deal with degaussing anyway?

You might be wondering, what does all this talk about degaussing have to do with TV sets?

In many ways, this comes down to the way the CRT works. At its most basic level, a cathode ray tube is a gigantic electron gun with the primary target being the screen that aims to show the images.

The YouTube channel Technology Connections, a Tedium favorite, has a great video describing how the CRT works in analog television sets, which you can watch here.

The thing with electrons, though, is that they are magnetically charged, and when magnets interact with one another, they cause problems. Think about that recent news story about how Apple’s MagSafe connectors in recent iPhones cause problems with pacemakers.

In many ways, magnets have a similar effect on CRTs—they screw the sets up. This is particularly the case with color, whose intensity can be negatively affected by magnets, basically confusing the set’s makeup of color in the process.

This clip of a guy going buck-wild with a neodymium magnet on a CRT is a great example of this in action. A strong magnet can force the electron gun to misfire, but on top of that, it shakes up the colors and makes them particularly trippy in a psychedelic sense. The black and white signal will generally return to position. The color won’t.

Now, this is where the need for degaussing comes in. Degaussing is the process of removing unwanted magnetic fields from an object, and they became particularly important in the era of the color TV.

In early color televisions produced before the mid-1960s or so, there was a need to periodically tune the screens that required the assistance of a TV repairman to help periodically tune the television to ensure the highest quality.

An unbylined syndicated 1966 article that ran in a number of newspapers described TV sets as “touchy” (and has some old-school gender politics in its lede, sadly) and said that older color television sets could take as long as an hour and a half to retune. The good news, however, is that technology was improving during this time and degaussers were often built into newer TV sets. (The whooshing effect that you might remember when an old TV set turned on? That was the degaussing coil.)

Still though, the piece noted that periodic technician work was necessary to keep the set working:

Although automatic or manual degaussers are part of better quality color television sets to demagnetize or counteract the earth’s magnetic field and cut down on impurities that louse up a picture, it may be necessary for the technician to degauss the set in a few months s after it is installed. He also 1 must be equipped to realign the picture so it will hold for at least another year.

The technology required to degauss a TV set was often promoted using terms like “color purifier” to help sell the idea that the sets looked significantly better than the old ones. The marketing messages around these sets became a bit over the top, to the point that Congressional hearings were held in the early 1970s to consider whether the FTC was doing enough to rein in misleading advertising claims. The long story short of all that: The technology used to purify the sets did work, but it was not unique by that point. Literally every color TV set under the sun had it.

And by the 1980s, computer monitors, which often dealt in far higher resolutions than television sets did, also had to rely on degaussing technology. The problem is, those old built-in degaussing coils don’t always work forever, which requires the use of external devices. (If you move a CRT around, it’s recommended that you degauss it.)

A bunch of them are on YouTube, and man, are they fun to watch. Let’s start with the one I teased earlier:

As you can see, a strong magnet totally ruined the effect of those color bars. And the degaussing coil built into the device, complete with its own button, wasn’t enough to fix it. But by carefully using an external degaussing coil—a round device that looks not unlike an old antenna—the user was able to slowly wave the coil around the screen and repair it. (These are on sale online, but not always in the large, round form.) The effect is dizzying to watch.

As the YouTube channel Arcade Repair Tips explains, this was also the case for old arcade machines, such as the 1942 machine used as a test subject.

But one does not necessarily need a special coil to pull off this trick. In this 2015 clip involving YouTube’s favorite game, the original Super Mario Bros., a neodymium magnet is used both to screw up the colors, and, by slowly waving back over a few minutes, to fix them.

But because this is Tedium and we must save the best for last, I share with you this video of a guy taking an electric drill to a computer screen. (Warning: it gets loud.) Not quite as effective as simply using a degaussing coil, but incredibly fun to watch.

If you were to show these videos to the Insane Clown Posse, they would call it a miracle.