CRT Art: Wobbulator

The Wobbulator is a black and white CRT television that has additional hardware to manipulate the electrons as they bombard the phosphor layer of the screen. It was created by [June Paik] and you can find it at The Experimental Television Center. [Blair Neal] took some time to share the background information and some video on this interesting device.

The television has a second ”yoke” of coils around the ray tube. The TV still functions normally with these coils installed, but running a signal through them can further manipulate the picture. Hook, them up to a function generator and you can get some pretty wild effects. In this case, the signals from a sound generator are controlling the coils, resulting in the audio/video artwork which you can view after the break.


24 thoughts on “CRT Art: Wobbulator

  1. Neat! I do wonder about the tube’s phosphor life though, since the original video signal has the potential for a full strength signal (that would normally be spread across the full screen) concentrated in one spot by the secondary coils. Kinda like how I was always warned to avoid strong concentrated stationary signals on oscilloscopes. Mind, CRTs are a dime a dozen these days so it’s likely not that important.

  2. As a matter of historical interest… there is actually a real piece of test equipment called a “wobulator.” What it amounts to is a sweep generator, and was used to align filters and tuned circuits.

    One way to achieve “wobulation” (my term) was to couple the shaft of a variable capacitor to the shaft of a motor. The capacitor was wired to the tank circuit of an oscillator.

  3. I hacked a TV into an oscilloscope in 1970. On the way I hooked up a half video horizontal and half vertical audio combination. I also wired the vertical coils out of phase resulting in the X display of live TV, as seen in one of the videos. A crude synth I made a couple of years later made some really cool vector patterns. I watched brightness and never burned a tube.

  4. “We control the horizontal, we control the vertical…”, neat hack, shame you didn’t post it a few weeks ago, it would have been perfect in a “Mad Scientists Lab” Haunted House.

  5. As a matter of metrological interest… there is actually a real piece of test equipment called a “wobulator.” What it amounts to is an off-axis rotating table and was used to calibrate accelerometers and vibration test equipment.

  6. @leadacid
    You need a kind of analogue spot-killer; rectify some of the X and Y signals and use it to overcome close-to-cutoff bias on the tube grid – automatic brightness control.

    The term Wobbulator comes from “Wobbling Oscillator” and these are still in use for aligning IF strips and other bandpass
    circuits, generally in the high-kHz to MHz range. By convention a Wobbulator differs from other tools like sweep generators in that the swept range is very confined, and it may have fixed output frequencies on common IF’s.


    This hack is not a Wobbulator but it is a pretty neat idea that deserves its own descriptive name “Raster Maniuplation Unit ” or RMU for short.

    Get seriously into it here…

  7. Nam June Paik’s stuff is super awesome. i had the pleasure of seeing a show of his quite a while ago (10 years?). most of his sculptures there used a CRT in some way, as well as some neat stuff with mini video projectors and mini CRTs. they dealt with the flow of information, active and passive media viewing, and what our expectations of mass media are.

    if Marshall McLuhan were a sculptor, he’d be Nam June Paik.

  8. Nice! I did an artist residency at the Experimental Television Center last year, and played with this very same Wobbulator for hours.

    If anyone else reading HAD is an artist with an interest in older technology, ETCenter is a true wonderland. They invite you to stay all by yourself in a very large room with nothing but AV equipment and a bed in the corner.

  9. Very very nice hack. Cathode Ray Tubes have become obsolete tech in the eyes of the normal consumer.

    But it still is such a nice tech and easy to manipulate. It’s the perfect thing to teach kids about magnetic fields and how to manipulate them. It translates the invisible into something visible.

    Just too bad it’s so bulky, and a bit dangerous (implosion risk).

  10. someone should try this with an old laptop display- capture the LVDS traffic for a coloured background from the old machine and store it then play back using a micro and serial E2PROM with high speed RAM buffer chips such as the 23K640.

    should be cool, just shift data around (or change the readback order) on the colour data while leaving the timing intact.

    a little tip, AA1 screens are relatively simple and have fewer LVDS lines so making things easier, as long as a serial e2prom with screen data is connected on the PC side interface to fool the laptop into outputting data no matter what is connected.

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