Jochen Saueracker
Electronic Media Review, Volume Six: 2019-2020
Cathode ray tube (CRT) televisions used to be a wide-spread presentation medium and they also became a structural part in many artworks since the rise of video art in the 1970s and 1980s. To experience the special qualities of a historic video image the viewers need the technical structure of the analog display. With nearly all picture tube televisions at the end of their lifetime new concepts to keep this iconic cultural machine alive for the future are urgently needed. We also face the fact that the manufacturing and maintenance structures for analog televisions has vanished. Three years ago Christian Draheim, a specialist for display systems, established a new workshop for the rebuilding of CRT picture tubes, a technique that was previously lost. This presentation describes the process of rebuilding a picture tube and focuses on the establishment of a predictive maintenance process to support CRT technology. The necessary steps for the near future to keep not only the picture tubes alive, but simultaneously the technical knowledge about the CRTs, are reviewed. The fragile equilibrium of artist, artwork, technology and time needs a preventive approach to be intelligible in the future.
The cathode ray tube (CRT) television was a very important device for the development of our information society, which is based on visual moving images. CRT technology even survived the first years of the digital revolution, before liquid crystal display (LCD) and other flat panel technologies were able to take over in many presentation environments.
The limited available screen sizes, the bulky body of the TV, and the image ratio created the basic formal language of video art. In order to keep the early analog, CRT-based video art alive in its own unique technical environment we have to reach out to learn about the possibilities to keep CRT technology functioning for the next generations (fig. 1). We have to acknowledge that the picture tube of the CRT television is way more than a technical presentation device, but it is also part of our cultural heritage.
Neither the CRT nor video art were isolated in our society. The ongoing technical evolution influenced them, and older technological products became obsolete and were replaced by new inventions. Often those developments were the result of new production possibilities, which is a major element of our technical evolution. In our society, “new is better” is always connected with technological development.
A television is a complex construction and its “raw material”—the glass, the circuit board, the ICs (integrated circuits)—are already the result of an industrial production process (fig. 2). The gradual development and change in the production processes led to the point that parts to service a CRT became rare or went out of production.
When no parts are available, service will become impossible. From there it is a short step until the knowledge about the function of CRT technology is lost, as no young technicians will get a chance to be trained in servicing these older devices and to gain experience in this field.
In video art the television combines two functions (fig. 3). In a sculpture it is part of the three-dimensional sculptural body. At the same time it is used as a display device that adds the moving video image to the artwork.
Most video works were made with the standard equipment of the time when they were created. Whether it was a “professional” or a “consumer” standard is another matter. The reasons for the choice of a certain model of television were manyfold. It could have been the financial situation or the technological or brand preferences of the artist, or it was just the random chance as the only equipment that was in reach.
Obsolescence is unavoidable with any technical object. On a personal level it is an easy decision to continue to use old technological items. At home, no art historical circumstances have to be taken into account. However, museums have to plan for the future and their decisions will affect the following generations. In the complex decision process of an institution the omnipresent “new is better” can lead to a compromise that is compromising the artwork.
It is already 5 minutes past 12:00 on the dial of CRT technology (fig. 4). When the future of a broken video artwork is discussed, in some cases it seems unavoidable to involve flat screen panels to allow the video content to be displayed. Other resources are limited. You will never find a suitable CRT television with a fresh lifetime on the secondhand market.
Flat screen televisions are the technical standard of today. If no other device is available we are stuck using one of them. Their panels are very complex constructions in themselves, in part built on a microscopic level. We cannot expect that the approach to restore a flat screen television will be feasible in the future.
The project to replace a CRT picture tube with a flat panel display often involves many parties: the artist if still alive, art historians, curators, restorers and technicians. With the shorter lifetime of an LCD and the likelihood that an identical display will not be produced anymore within a few years, this complex decision process is not finalized, but rather placed in the hold-file.
In the search for possible solutions, hybrids have reached museum floors (fig. 5). A remarkable device was made from a 1970s television produced in East Germany, combined with a flat panel. It is a beautiful restored object and one can sense the affection that went into the body when it was rebuilt. However, from the first impression, with no moving image displayed, it looks more like a microwave oven. It is hard to imagine that this television will be able to represent Nam June Paik’s iconic Zen for TV (1963).
First of all it would not be able to follow the concept of a technically manipulated CRT television that reduces a full image to one line. But even when the line of the image is produced in a different way, the visual appearance would be confusing as the object would represent an artwork created in the early 1960s. A technically savvy visitor might wonder how the artist was able to use a flat screen at that time.
In our foundation we are facing the same problem. The Shigeko Kubota Video Art Foundation is based on the heritage of Shigeko Kubota (1937-2015), who was part of the first generation of video artists in New York City. One of our aims is to revive her artworks from the 1970s and 1980s. For some of the works that we restore for upcoming exhibitions, not enough CRT televisions are available.
Every artwork needs an individual approach and a unique solution. With research and tests we found solutions to reduce the alienating impression of an LCD panel replacing a CRT in a sculptural environment (fig. 6). However the color and the physical impression are different, and a replacement should only be used as a temporary possibility until a better solution is within reach.
The production process of a CRT tube was complex and economically feasible only on a large scale (fig. 7). Today ecological reasons also forbid the re-installation of a similar production line (Socolof 2005).
Parallel to the production industry, a workshop culture existed. Their job was to refurbish individual deficient products and to rebuild tubes that were worn out after a lifecycle of use. A CRT tube was a precious item; it was reasonable to invest in a second lifetime. Displays that were used in television stations, hospitals, airports or military bases were treated on a regular basis. These workshops combined different trades, as they had to handle glass, heat, gases, and electronics. Most of their machinery tools were developed in-house and custom-made.
The picture tubes consist of three different parts of glass (fig.8):
- The very thick front glass
- The glass, that shapes the body
- The neck glass, the tube-like extension at the end.
Inside the neck glass sits the electron emitting system. There is a small fourth piece of glass at the end of the system (fig. 9). This bottom glass closes off the neck glass at the rear end of the tube and the contact pins lead through it while maintaining the necessary vacuum for the CRT to function.
Two elements age within a picture tube. One is the heated metal element in the center of the system, which emits the electrons. Here the number of electrons emitted can decrease, which results in a dim and faint picture. The second element is the getter, a barium-filled container in the shape of a coin. The getter hangs from the system into the tube’s body like a tongue. It absorbs gas molecules in order to keep the vacuum clean. However, its absorption capacity is limited. When this material, mostly barium, is consumed the picture will also turn faint and dim.
Only a few people still have the hands-on experience to rebuild picture tubes. At the time they were originally made, very few people thought about the future and took care to collect materials like electron emitting systems, tubes of neck glass, etc. The materials are rare and the machines cannot be bought anymore, except for some mostly defunct relics on eBay (fig. 10). They have to be re-engineered and built onsite to the specific purpose needed for the workflow.
To my knowledge only one company, Colorvac (www.colorvac.de), in Leverkusen, Germany still offers CRT picture tube rebuilding. Their workflow also includes the preparation of the circuit boards. On the board the critical parts are identified and get exchanged, with the goal to increase the television’s lifetime.
The rebuilding process takes about 6 to 10 hours and has the following steps:
- The tube is carefully cut open
- The old system is removed
- The neck glass is extended with a small new piece
- The new system is placed inside
- The bottom glass of the system is connected to the neck glass
- In the oven, at a temperature of 400ºC, the vacuum is established inside the tube
- Finally the tube is sealed (fig. 11)
- The tube and the getter have to be activated by high voltage
- Tests and adjustments of the tube inside the television are performed.
A link to a video of this process can be found in the references below.
Ten years ago barns full of used CRTs were still available. The secondhand market has changed and now it is nearly impossible to find identical models in larger numbers. Some museums prepared themselves by stockpiling televisions that were in line with equipment used in the artworks of the collection. Not all have a large storage available like ZKM (Center for Art and Media) in Karlsruhe, Germany. It seems an ideal situation, but there is a downside, as technicians expect that 90% of the stored items cannot be used anymore (Liam Ohainnin, interview, Oct 26, 2019). However it is safer to follow this path of stockpiling until the functioning 10% that will be used in the future can be clearly identified (fig. 12).
Electronics age even without being in use. Capacitors become dry and might give up in a few minutes when the television is switched on after many years of storage (Christian Draheim, interview, Oct 17, 2019). The feeling of being prepared by a full storage of machinery alone is deceptive. A prescient collection of devices needs to be accompanied by a strategy of regular operation maintenance routines.
After a long time in storage, televisions should not just be plugged in. Damage that happens at this moment can easily multiply within the machine and will hurt additional parts. To avoid things going wrong at this moment, one could for example raise the current slowly with the help of an isolation transformer until it reaches the working level for the television (Christian Draheim, interview, Oct 17, 2019).
To prepare a storage environment for the future, a precise analysis of the stored devices will help to reduce the amount of necessary spare parts to a manageable number. Ideally a storage has to turn into an active entity. This is a difficult thought in times when many institutions drastically reduce their staff. A private collection in Germany chose a different approach and gave their overstock of televisions into commercial hands and is now renting when exhibitions of larger artworks call for additional equipment. On one hand this creates extra costs for the project, but on the other hand it means less cost in storage and maintenance. Plus the ease of mind to have workable machinery, including sufficient backup, available if needed.
Theoretically a picture tube can be rebuilt over and over again. The circuit boards however need a similar amount of attention. Many boards are built with proprietary parts and today it is difficult to find documentation for them. This makes repair or replacement difficult and time-consuming.
Certain parts, such as flyback transformers, are not available anymore (fig. 13). However with continuous effort and analysis these parts can be re-engineered (Axel Paap, interview, Oct 17, 2019). At this level a workshop has to mirror various industrial processes, and this is a challenge from technical and economic sides. The biggest challenge is to keep or recover the knowledge to handle all that is needed to fulfill the requirements. The places to gain experience in handling the equipment and the technology are rare and very often this knowledge is not handed down to the next generation anymore.
The CRT television has to be preserved to allow the presentation of video art in its original technical context. An essential part of this art form is lost without the proper equipment.
This also means that CRT technology and the knowledge about this technology have to be preserved. A few pockets of people with knowledge are still active. Museums and private collections around the globe have to recognize their stake in keeping this knowledge alive. Otherwise they will not be able to succeed with their mission to preserve our cultural heritage.
It is necessary to act if we want to keep works of analog video art available in a way that they can be experienced in their specific and unique functionality by following generations (fig. 14).
Let us keep the world in a good shape.
REFERENCES
Socolof, Maria Leet, Jonathan G. Overly, and Jack R. Geibig. 2005. “Environmental Life-Cycle Impacts of CRT and LCD Desktop Computer Displays.” Journal of Cleaner Production, Life Cycle Assessment, 13 (13-14): 1281–94. doi:10.1016/j.jclepro.2005.05.014.
SOURCE OF MATERIALS
Florian Draheim, Colorvac, 2020
http://colorvac.de/
Rebuilding of CRT television available at: https://youtu.be/5NtdH_YnZC0
AUTHOR
Jochen Saueracker
Curator, Archivist
Shigeko Kubota Video Art Foundation, NYC
jochen@shigekokubotavideoartfoundation.org