video technology, machines, equipment

Open reel and video cassette machines, equipment and digitisation technology used in the Greatbear video tape transfer studio

Philips VCR – the first home video cassette recorder

Graphics for Philips VCR in black, white and green with striking Op-Art feel

Graphic design for Philips VC-45 and VC-30 VCR tape boxes in the Greatbear collection

For thegreatbear.co.uk, I get to photograph and document racks and racks of beautiful 'obsolete' tape machines in the Greatbear studio. From time to time pictures of our machines pop up elsewhere online (I'm convinced our machines are the best-looking on the internet), and this month one of our Philips N1500 VCRs is featured in Australian electronics magazine Silicon Chip (May 2021).

The siliconchip.com.au article describes Philips' development of VCR: the first cassette-based video tape recording system designed for domestic use, following the success of their revolutionary Compact Cassette audio tapes, recorders and players (1962 onwards). This is set in the context of U-matic, the Panasonic Video Cartridge, Betamax and VHS.

The article is part 3 of a well-researched and illustrated feature series on The History of Video Tape. Scroll down for a text extract from the article - we recommend subscribing to the whole series.

top-loading Philips N1500 recorder open, with cassette loaded

Philips N1500 VCR with elevator open and loaded with VC45 cassette. Note buttons for tuning to ITV, BBC1 and BBC2 labelled with red Dymo tape.

"Philips [had] entered the domestic open-reel market with half-inch VTRs beginning with their 1969 release of the desktop LDL-1000. Although easy to use, it lacked a tuner, forcing users to have existing TV receivers modified to supply video and audio signals for the VTR. Such modified sets were known as receiver monitors.

The LDL-1000 achieved some success, but recalling the success of their audio Compact Cassette system (siliconchip.com.au July 2018), Philips began development of a cassette system for video recording.

Their N1500, released in 1972 (just one year after Sony’s U-matic), offered an integrated design. Containing a tuner and a timer and able to supply a standard television signal output, the N1500 hit the spot with consumers, except for the problem of tape length. The N1500 can claim to be the world’s first domestic VCR (video cassette recorder).

Philips’ VCR system mechanism, like their compact cassette mechanism, was offered royalty-free to manufacturers who agreed to maintain the design standard and use the VCR logo. You can see a video of a VCR tape loading at https://youtu.be/9-Bw8m65mVY

The VCR cassette stacked the supply and [take-up]reels above each other in a coaxial design. At only 125 x 145 x 40mm, it was much more compact than the standard U-matic cassette.

Its width (under 60% that of U-matic) helped moderate the size of the entire tape drive mechanism. While this elegant solution offered a genuinely compact medium, the complexity of its threading mechanism meant that its reliability was only fair.

Using a half-inch tape with a conventional 180° degree omega wrap, the Philips VCR was able to offer 60-minute record/play times at the CCIR/PAL speed of 14.29cm/s (5.63ips).

Philips attempted to market to the United States in mid-1977, but NTSC’s higher field rate (60Hz vs CCIR/PAL’s 50Hz) forced an increase in tape speed to around 17.2cm/s (6.8ips), giving only 50 minutes for a cassette. A thinner tape, offering the full 60 minutes for NTSC, proved unreliable in use.

Other compromises finally made their VCR unsuitable for the American and other NTSC markets, while the introduction of VHS in 1977 convinced Philips to abandon the US market. As a result, their VCR was only marketed to the UK, Europe, Australia and South Africa.

Philips tape loading is simpler than that of the U-matic. Sony had put every interaction (transport, heads and guides) in the external tape path. Philips cleverly used two cassette doors: an upwards-hinging one at the front for tape extraction, and a sliding one at the right, allowing the audio/control track head and the pinch roller to intrude into the cassette.

Video entry and exit guides, and the capstan, also intruded vertically into the cassette as it was loaded downwards, giving much a more compact tape transport than that of U-matic. The pinch roller and audio/control heads, mounted on a pivoted arm, were swung into place for playback and recording.

Where the U-matic head drum was designed with slip-ring contacts from the heads to the VCR electronics, Philips used a rotary transformer design that had already been used in Ampex 1-inch open-reel VTRs. Although more difficult to design and manufacture, the rotary transformer overcame noise and signal loss caused by slip-ring corrosion or misalignment. It would become the design of choice in Beta, VHS and following formats.

The N1500 was developed as far as the N1520 production model. Dispensing with the inbuilt tuner, the N1520 offered record/playback and full electronic assembly/insert video and audio editing. Released in 1973, it beat Sony’s VO-2850 workalike U-matic editor to market by a full year.

Regrettably, the Philips VCR format suffered from unreliable tape loading/handling, and that dreaded one-hour time limit.

Philips did develop a long-play VCR, the N1700 series, by halving the tape speed. Not released until 1977, when the Sony-JVC/Beta-VHS melee was well underway, the Philips VCR lapsed into obscurity. "

.................................................................

Extract from The History of Videotape – part 3 Cassette Systems by Ian Batty, Andre Switzer & Rod Humphris, Silicon Chip, May 2021

image of magazine page including photograph of Greatbear Phillips N1500 machine and graphic illustrations of VCR and U-matic cassettes

Preview of page from www.siliconchip.com.au The History of Video Tape - Part 3: Cassette Systems

Stripe of black video tape held diagonally between two white plastic spools inside cassette housing

Philips N1500 VC30 video cassette with shell open to show tape between coaxial spools

square-ish N1500 video cassette with rulers indicating width 12.7 cm by height 14.5cm

Philips N1500 cassette dimensions: 12.7 x 14.5 x 3.8 cm

Posted by melanie in video tape, video technology, machines, equipment, 0 comments

Video Art & Machine Obsolescence

multiple stills from BBC documentary showing Jim Moir and Greatbear video equipment in a mock-up studio

Stills from BBC4's "Kill Your TV: Jim Moir’s Weird World of Video Art", showing vintage video equipment from the Greatbear studio with researcher Adam Lockhart and artists Catherine Elwes and George Barber © Academy 7 Productions 2019.

At Greatbear we have many, many machines. A small selection of our analogue video players, CRT monitors, cameras, cables and tapes recently found work as props (both functional and decorative) in the BBC documentary “Kill Your TV: Jim Moir’s Weird World of Video Art”, on BBC iPlayer here.

From the BBC website: “Jim Moir, aka Vic Reeves, explores video art, revealing how different generations hacked the tools of television to pioneer new ways of creating art."

Our obsession with collecting and restoring rare video equipment is vital for our work. As technology developed through the latter half of the 20th century, dozens of different formats of video tape were created - each requiring specialist equipment to play it back: equipment which is now obsolete. The machines have not been manufactured for decades and the vast majority of them have been scrapped.

Those that remain are wearing out - the rotating head drums that read video tape have a finite number of working hours before they need replacement. Wear to the head drum tips is irrevocable, and the remaining few in existence are highly sought-after.

Even TV companies, where U-matic, Betacam and countless other formats of VTR machine were once ubiquitous, no longer have access to the machines and monitors we provided for “Kill Your TV”.

It is a similar conundrum for the artists who produced work with older video technology, and for the galleries and museums who hold collections of their work. We have recently been working on a fascinating project with specialist art conservator for time-based media, Brian Castriota and the Irish Museum of Modern Art, transferring important video artworks produced between 1972 - 2013 from multiple video tape formats, by artists including Isaac Julien, Gillian Wearing and Willie Doherty - more on this in a future blog post!

conceptual immateriality & the material device

In "Kill Your TV", Jim Moir describes a demonstration of David Hall’s "Vidicon Inscriptions" (1973) as “an electronic image that doesn’t really exist in a physical space” which nevertheless relies on the quirks of (very physical) vintage video equipment for its enactment.

Artist Peter Donebauer refers specifically to immateriality inherent to his 1974 video art piece “Entering” (broadcast via the BBC’s arts programme “2nd House”). PD: "Technically, the real core of this is the signal. It made me think about what this medium was, because it’s not material in the same way as painting, sculpture or even performance, dance, film - almost anything that has physicality.”

But for a signal to be perceived, it needs to be reproduced by a physical device capable of reading it. The dangers facing video artwork preservation lie not only in the fragility of the tape itself, but in the disappearance of rare playback machines and the specialist tools for their maintenance and repair; of the service manuals, calibration tapes and the expertise needed to set them up.

The 'tools of television' relished in "Kill Your TV" are the material devices we are striving to save, repair and maintain.

links & further reading:

Read about our facilities to transfer video made with the Sony Portapak system featured in the documentary: Sony 1/2 inch Portapak (EIAJ) / CV2100 / CV2000 open reel video tape

Our work with Videokunstarkivet, an exciting archival project mapping all the works of video art that have been made in Norway since the mid-1960s, funded by the Norwegian Arts Council.

“Kill Your TV: Jim Moir’s Weird World of Video Art” was made for BBC4 by Academy 7 Productions

 

Posted by melanie in video tape, video technology, machines, equipment, 0 comments

VHS – more obsolescence threats

S-VHS-Machine-Great-Bear-Analogue-Digital-Media

Earlier this month we wrote an article that re-appraised the question of VHS obsolescence.

Variability within the VHS format, such as recording speeds and the different playback capacities of domestic and professional machines, fundamentally challenge claims that VHS is immune from obsolescence threats which affect other, less ubiquitous formats.

The points we raised in this article and in others on the Great Bear tape blog are only heightened by news that domestic VHS manufacture is to be abandoned this month.

It is always worth being a bit wary of media rhetoric: this is not the first time VHS’s ‘death’ has been declared.

In 2008, for example, JVC announced they would no longer manufacture standalone VHS machines.

Yet Funai Electric’s announcement seems decidedly more grave, given that ‘declining sales, plus a difficulty in obtaining the necessary parts’ are the key reasons cited for their decision.

To be plain here: If manufacturers are struggling to find parts for obsolete machines this doesn’t bode well for the rest of us.

The ‘death’ of a format is never immediate. In reality it is a stage by stage process, marked by significant milestones.

The announcement last week is certainly one milestone we should take notice of.

Especially when there are several other issues that compromise the possibility of effective VHS preservation in the immediate and long term future.

What needs to be done?

As ever, careful assessment of your tape collection is recommended. We are always on hand to talk through any questions you have.

Posted by debra in video tape, video technology, machines, equipment, 0 comments

SONY’s U-matic video cassette

Introduced by SONY in 1971 U-matic was, according to Jeff Martin, 'the first truly successful videocassette format'.

Philips’ N-1500 video format dominated the domestic video tape market in the 1970s. By 1974 U-matic was widely adopted in industrial and institutional settings. The format also performed a key role in the development of Electronic News Gathering. This was due to its portability, cost effectiveness and rapid integration into programme workflow. Compared with 16mm film U-matic had many strengths.

The design of the U-matic case mimicked a hardback book. Mechanical properties were modelled on the audio cassette's twin spool system.

Like the Philips compact audio cassette developed in the early 1960s, U-matic was a self-contained video playback system. This required minimal technical skill and knowledge to operate.

There was no need to manually lace the video tape through the transport, or even rewind before ejection like SONY's open reel video tape formats, EIAJ 1/2" and 1" Type C. Stopping and starting the tape was immediate, transferring different tapes quick and easy. U-matic ushered in a new era of efficiency and precision in video tape technology.

Mobile news-gathering on U-matic video tape

Emphasising technical quality and user-friendliness was key to marketing U-matic video tape.

As SONY's product brochure states, 'it is no use developing a TV system based on highly sophisticated knowledge if it requires equally sophisticated knowledge to be used'.

'The 'ease of operation' is demonstrated in publicity brochures in a series of images. These guide the prospective user through tape machine interface. The human operator, insulated from the complex mechanical principles making the machine tick only needs to know a few things: how to feed content and direct pre-programmed functions such as play, record, fast forward, rewind and stop.

New Applications

Marketing material for audio visual technology often helps the potential buyer imagine possible applications. This is especially true when a technology is new.

For SONY’s U-matic video tape it was the ‘very flexibility of the system’ that was emphasised. The brochure recounts a story of an oil tanker crew stationed in the middle of the Atlantic.

After they watch a football match the oil workers sit back and enjoy a new health and safety video. ‘More inclined to take the information from a television set,’ U-matic is presented as a novel way to combine leisure and work.

Ultimately ‘the obligation for the application of the SONY U-matic videocassette system lies with the user…the equipment literally speaks for itself.’

International Video Networks

Before the internet arrived, SONY believed video tape was the media to connect global businesses.

'Ford, ICI, Hambro Life, IBM, JCB...what do these companies have in common, apart from their obvious success? Each of these companies, together with many more, have accepted and installed a new degree of communications technology, the U-matic videocassette system. They need international communication capability. Training, information, product briefs, engineering techniques, sales plans…all can be communicated clearly, effectively by means of television'.

SONY heralded videotape's capacity to reach 'any part of the world...a world already revolutionised by television.' Video tape distributed messages in 'words and pictures'. It enabled simultaneous transmission and connected people in locations as 'wide as the world's postal networks.' With appropriate equipment interoperability between different regional video standards - PAL, NTSC and SECAM - was possible.

Video was imagined as a powerful virtual presence serving international business communities. It was a practical money-saving device and effective way to foster inter-cultural communication: 'Why bring 50 salesmen from the field into Head Office, losing valuable working time when their briefing could be sent through the post?'

Preserving U-Matic Video Tape

According the Preservation Self-Assessment Program, U-matic video tape ‘should be considered at high preservation risk’ due to media and hardware obsolescence. A lot of material was recorded on the U-matic format, especially in media and news-gathering contexts. In the long term there is likely to be more tape than working machines.

Despite these important concerns, at Greatbear we find U-matic a comparatively resilient format. Part of the reason for this is the ¾” tape width and the presence of guard bands that are part of the U-matic video signal. Guard bands were used on U-matic to prevent interference or ‘cross-talk’ between the recorded tracks.

In early video tape design guard bands were seen as a waste of tape. Slant azimuth technology, a technique which enabled stripes to be recorded next to each other, was integrated into later formats such as Betamax and VHS. As video tape evolved it became a whole lot thinner.

In a preservation context thinner tape can pose problems. If tape surface is damaged and there is limited tape it is harder to read a signal during playback. In the case of digital tape, damage on a smaller surface can result in catastrophic signal loss. Analogue formats such as U-matic, often fare better, regardless of age.

Paradoxically it would seem that the presence of guard bands insulates the recorded signal from total degradation: because there is more tape there is a greater margin of error to transfer the recorded signal.

Like other formats, such as the SONY EIAJ, certain brands of U-matic tape can pose problems. Early SONY, Ampex and Kodak branded tape may need dehydration treatment ('baked') to prevent shedding during playback. If baking is not appropriate, we tend to digitise in multiple passes, allowing us to frequently intervene to clean the video heads of potentially clogging material. If your U-matic tape smells of wax crayons this is a big indication there are issues. The wax crayon smell seems only to affect SONY branded tape.

Concerns about hardware obsolescence should of course be taken seriously. Early 'top loading' U-matic machines are fairly unusable now.

Mechanical and electronic reliability for 'front loading' U-matic machines such as the BVU-950 remains high. The durability of U-matic machines becomes even more impressive when contrasted with newer machines such as the DVC Pro, Digicam and Digibeta. These tend to suffer relatively frequent capacitor failure.

Later digital video tape formats also use surface-mounted custom-integrated circuits. These are harder to repair at component level. Through-hole technology, used in the circuitry of U-matic machines, make it easier to refurbish parts that are no longer working.

 

Transferring your U-matic Collections

U-matic made video cassette a core part of many industries. Flexible and functional, its popularity endured until the 1990s.

Greatbear has a significant suite of working NTSC/ PAL/ SECAM U-matic machines and spare parts.

Get in touch by email or phone to discuss transferring your collection.

Through-hole technology

Posted by debra in digitisation expertise, video tape, video technology, machines, equipment, 0 comments

Philips N-1502 TV Recorder

The front page of the Philips N-1502 TV Recorder catalogue presents a man peering mournfully into a dark living room. A woman, most probably his wife, drags him reluctantly out for the evening. She wants to be social, distracted in human company.

Philips-N1502-marketing-catalogue The N-1502 tape machine is superimposed on this unfamiliar scene, an image of a Grand Slam tennis match arises from it, like a speech bubble, communicating the machine’s power to capture the fleeting live event. The man’s stare into the domestic environment constructs desire in a way that feels entirely new in 1976: a masculinity that appropriates the private space of the home, now transformed as a location where media events are transmitted and videotaped.

The man’s gaze is confrontational. It invites those looking to participate in a seductive, shared message: videotape-in the home-will change your life forever.

In the 1970s Philips were leading figures in the development of domestic video tape technology. Between 1972 and 1979, the company produced seven models of the N-1500 video ‘TV recorder’. It was the first time video tape entered the domestic environment, and the format offered a number of innovations such as timed, unattended recording (‘busy people needn’t miss important programmes’), an easy loading mechanism, a built in TV tuner, a digital electronic time switch and stop motion bar.

The N-1500 converged upon several emergent markets for video tape. While SONY’s hulking U-matic format almost exclusively targeted institutional and industrial markets, the N-1500 presented itself as a more nimble alternative: ‘Compact and beautifully designed it can be used in schools, advertising agencies, sale demonstrations and just about everywhere else.’

Used alongside the Philips Video Camera, the N-1500 could capture black and white video, offering ‘a flexible, economic and reliable’ alternative to EIAJ/ porta-pak open reel video. Marketing also imagined uses for sports professionals: practices or competitive games could be watched in order to analyse and improve performance.

Philips N1502-marketing-brochure Although N-1500 tape machines were very expensive (£649 [1976]/ £4,868.38 [2016]), the primary market for the product was overwhelmingly domestic. In 2016 we are fairly used to media technologies disrupting our intimate, every day lives. We are also told regularly that this or that gadget will make our lives easier.

Such needs are often deliberately and imaginatively invented. The mid-1970s was a time when video tape was novel, and its social applications experimental. How could video tape be used in the home? How would it fit into existing social relationships? The marketing brochure for the Philips N-1502 offer compelling evidence of how video tape technology was presented to consumers in its early days.

One aspect highlighted how the machine gave the individual greater control of their media environment: ‘Escape from the Dictatorship of TV Timetables’!

The VCR could also help liberate busy people from the disappointment of missing their favourite TV programmes, ‘if visitors call at the moment of truth don’t despair. Turn the TV off and the VCR on.’

In the mid 1970s domestic media consumption was inescapably communal, and the N-1500 machine could help sooth ‘typical’ rifts within the home. ‘You want to see a sports programme but your wife’s favourite serial is on the other channel. The solution? Simple. Just switch on your Philips VCR.’

Owning the N-1500 meant there would be ‘no more arguments about which channel to select – you watch one while VCR makes a parallel recording from another.’ Such an admission tells us a lot about the fragility of marriages in the 1970s, as well as the central place TV-watching occupied as a family activity. More than anything, the brochure presents videotape technology as a vital tool that could help people take control over their leisure time and negotiate the competing tastes of family members.

N-1500 transfers

As the first domestic video tape technology, the Philips N-1500 ‘set a price structure and design standard that is still unshaken,’ wrote the New Scientist in 1983.

In a preservation context, however, these early machines are notoriously difficult to work with. Tapes heads are fragile and wear quickly because of a comparatively high running tape speed (11.26 ips). Interchange is often poor between machines, and the entry/ exit guides on the tape path often need to be adjusted to ensure the tapes track correctly.

Later models, the N-1700 onwards, used slant azimuth technology, a recording technique patented by Professor Shiro Okamura of the University of Electronic Communications, Tokyo in 1959. Slant azimuth was adopted by JVC, Philips and SONY in the mid-1970s, and this decision is heralded as a breakthrough moment in the evolution of domestic video tape technology. The technique offered several improvements to the initial N-1500 model, which used guard bands to prevent cross talk between tracks, and the Quadruplex technology developed by Ampex in the late 1950s. Slant azimuth meant more information could be recorded onto the tape without interference from adjacent tracks and, crucially, the tape could run at a slower speed, use less tape and record for longer.

In general, the design of the N-1500’s tape path and transport doesn’t lend itself to reliability.

As S P Bali explains:

‘One reason for the eventual failure of the Philips VCR formats was that the cassette used coaxial spools—in other words, spools stacked one on top of the other. This means that the tape had to run a skew path which made it much more difficult to control. The tape would jam, and even break, especially ageing cassettes.’ [1]

Philips N1500 (top) & Philips N1702 (bottom) machines in the Greatbear studio

Such factors make the Philips N-1500 series an especially vulnerable video tape format. The carrier itself is prone to mechanical instability, and preservation worries are heightened by a lack of available spare parts that can be used to refurbish poorly functioning machines.

If you have valuable material recorded on this format, be sure to earmark it as a preservation priority.

Notes

[1] S P Bali (2005) Consumer Electronics, Delhi: Pearson Education, 465.

Posted by debra in video tape, video technology, machines, equipment, 0 comments

Video and Technologies of Consciousness: An Interview with Peter Sachs Collopy

We first encountered the work of Media Historian Peter Sachs Collopy during research for a previous blog article about video synthesizers.

His work was so interesting we invited Peter to do a short interview for the blog. Thanks Peter for taking time to respond, you can read the answers below!

We were really struck by your description of early video as a technology of consciousness. Can you tell us a bit more about this idea? Did early users of portable video technology use video in order to witness events?

Absolutely! Technology of consciousness is a term I found in communications scholar Fred Turner’s work, particularly his essay on the composer Paul DeMarinis (“The Pygmy Gamelan as Technology of Consciousness,” in Paul DeMarinis: Buried in Noise, ed. Ingrid Beirer, Sabine Himmelsbach, and Carsten Seiffarth [Heidelberg: Kehrer Verlag, 2010], 23–27). Every technology affects how we think and experience the world, but I use this phrase specifically to refer to technologies whose users understood that they were doing so. The quintessential examples are psychedelic drugs, which people use specifically in order to alter their consciousness. For many videographers in the 1960s and 1970, video was like a drug in that it helped a person see the world in new ways; a cartoon in the magazine Radical Software proclaimed, for example, that “Video is as powerful as LSD” (Edwin Varney, Radical Software 1, no. 3 [Spring 1971]: 6). Part of all of this was that following Aldous Huxley, people believed that psychedelics made it possible to break down the barriers of the individual and share consciousness, and following media theorist Marshall McLuhan and theologian/paleontologist Pierre Teilhard de Chardin, they believed that new electronic media had the same effects. In my research, I trace these ways of thinking about technologies of consciousness back to the influence of philosopher Henri Bergson at the turn of the century. So yes, people were using video to witness events, but just as importantly they were using video to witness—and to reinterpret, and even to constitute—themselves and their communities.

Video is powerful as LSD As specialists in the transfer of video tapes we often notice the different aesthetic qualities of porta-pak videouMatic, VHS and DVCAM, to name a few examples. How does ‘the look’ of a video image shape its role as a technology of consciousness? Is it more important how these technologies were used?

It’s striking how little discussion of aesthetics and the visual there was in venues like Radical Software, though of course art critics started writing about video in these terms in the late 1960s. People were often more interested in what differentiated the process of shooting video from film and other media, in its ability to be played back immediately or in its continuity as an electronic technology with the powerful media of television and computing. Sony’s first half-inch videotape recorders, using the CV format, had only half the vertical resolution of conventional television. CV decks could still be hooked up to ordinary television sets for playback, though, so they still became a way for users to make their own TV.

What’s your favourite piece of video equipment you have encountered in your research and why?

I have several Sony AV-3400 portapaks that I’ve bought on eBay, none of them quite in working order. Those were the standard tool for people experimenting with video in the early 1970s, so I’ve learned a lot from the tactile experience of using them. I also have a Sony CMA-4 camera adaptor which provides video out from an AVC-3400 portapak camera without using a deck at all; I’ve used that, along with digital equipment, to make my own brief video about some of my research, “The Revolution Will Be Videotaped: Making a Technology of Consciousness in the Long 1960s (see below).”

In your research you discuss how there has been a continuity of hybrid analogue/ digital systems in video art since the 1970s. Given that so much of contemporary society is organised via digital infrastructures, do you think analogue technologies will be reclaimed more widely as a tool for variability in the future, i.e., that there will be a backlash against what can be perceived as the calculating properties of the digital?

I’m not sure a reclaiming of analog technologies will ever take the form of an explicit social movement, but I think this process is already happening in more subtle ways. It’s most apparent in music, where vinyl records and analog synthesizers have both become markers of authenticity and a kind of retro cool. In the process, though, analog has shifted from a description of machines that worked by analogy—usually between a natural phenomenon such as luminance and an electrical voltage—to an umbrella term for everything that isn’t digital. In the context of moving images, this means that film has become an analog technology as the definition of analog has shifted—even though analog and digital video are still more technically similar, and have at times been more culturally related, than film and analog video. So yes, I think there’s a backlash against precision, particularly among some artistic communities, but I think it’s embedded in a more complex reclassification of technologies into these now dominant categories of analog and digital.

Posted by debra in video tape, video technology, machines, equipment, 0 comments

Red Beat: U-matic Low Band Transfer and Video Synthesizers

The latest eclectic piece of music history to be processed in the Greatbear Studio is a U-matic Low Band video of ‘Dream/Dream Dub’ by Red Beat, a post-punk band that was active in the late 1970s and early 1980s. Despite emitting a strong wax crayon-like odour that is often a sure sign of a degraded U-matic tape, there were no issues with the transfer.

Red Beat formed in High Wycombe in 1978. After building up in solid fan base in the Home Counties they moved to London to pursue their musical ambitions. In London they recorded an EP that was released on Indie label Malicious Damage and did what most do it yourself punk bands would have killed to do: record a John Peel session. They also supported bands such as U2, Killing Joke, Thompson Twins and Aswad.

Originally inspired by New Wave acts such as Blondie and XTC, their later sound was more experimental, influenced by bands like PiL, Siouxsie and the Banshees and Killing Joke.

Roy Jones, singer and driving force behind getting Red Beat’s archive digitised explains that ‘we wrote together by jamming for hours till something sparked.’ Later evolutions of the band had more of a ‘pop orientation’ underscored by ‘a dark sound that fused Punk and Reggae and Tribal Beats.’ Songs by the band include the sci-fi inspired ‘Visit to Earth’ , ‘Ritual Sacrifice,’ a lamentation on the futility of war and ‘Searching for Change’, which explores the need for personal, spiritual and political transformation.

Video Synthesizers

In 1982 Red Beat formed their own indie label, Manic Machine Products, and released two further singles ‘See/Survival’ and ‘Dream/Dream Dub’, both distributed by Rough Trade.

The video of ‘Dream/ Dream Dub’ is the only existing video footage of the band at the time.

Roy’s motivation for sending it to Greatbear was to get the best quality transfer that he will then remaster, add a clean sound track to and upload to the Red Beat youtube playlist.

Of particular interest is ‘Dream/ Dream Dub’s use of video synthesizer footage which was, Roy tells me, ‘quite unique at the time. This footage was then edited with two tape analogue technology which is slow and not as accurate as modern editing.’

As Tom DeWitt explains ‘technically, the video synthesizer is more complex than its audio cousin. Video signals cover a frequency spectrum 100 times greater than audio and must be constructed according to a precise timing synchronization which does not exist in the one dimensional audio signal.’

In the early 1960s and 1970s, synthesizing video images was an emergent form of video art. Artists Shuya Abe and Nam June Paik created one of the first ‘video devices intended to distort and transform the conventional video image.’ [1] Part of their aim was to challenge the complacent viewer’s trans-fixation on the TV screen.

In the 1970s the artistic palette of the video synthesizer evolved. Bill Hearn was instrumental in developing ‘colorisation’ in 1972, and in 1975, Peter Sachs Collopy tells us, he incorporated this tool into ‘a full-featured synthesizer, the Videolab, which also produced effects like switching, fades, dissolves, wipes, and chromakey.’ [2]

‘Colourisation’ is a big feature of the Red Beat video. It refers to the ability to change the appearance of colours by mixing either the red, blue and green elements or the video colour parameters: luminance, chrominance and hue. In ‘Dream/ Dream Dub’ the red, green and blue colourisation is applied, accentuating the primary colours to give the image a garish, radioactive and extra-terrestrial quality.

Want more Red Beat?

If this article has sparked your curiosity about Red Beat you can buy their albums Endless Waiting Game and The Wheel from itunes.

The final word about the band must go to Roy: ‘We were part of a vibrant music scene. Other people enjoyed more success than us but we had a great time and created some great memories. I don’t think many people would remember our music but there are a few who buy our albums and remember seeing us live. We created our own bit of rock’n roll history and it’s worth documenting.’ [3]

Notes

[1] Chris Meigh-Andrews, A History of Video Art (London: Bloomsbury, 2013), 136.

[2] Peter Sachs Collopy ‘Video Synthesizers: From Analog Computing to Digital Art,’ IEEE Annals of the History of Computing, 2014, 74-86, 79.

[2] Thank you to Roy for generously sharing his memories of Red Beat and to Peter Sachs Collopy for sharing his research.

Posted by debra in video tape, video technology, machines, equipment, 0 comments

D-1, D-2 & D-3: histories of digital video tape

Enormous D-1 cassette held in hand

Large D-1 cassette dimensions: 36.5 x 20.3 x 3.2cm

D-2 tape with rulers showing size

D-2 cassette dimensions: 25.4 x 14.9 x 3cm

D-3 tape with rulers showing size

D-3 cassette size M: 21.2 x 12.4 x 2.5 cm

At Greatbear we carefully restore and transfer D-1, D-2, D-3, D-5, D-9 and Digital-S tapes  to digital file at archival quality.

Early digital video tape development

Behind every tape (and every tape format) lie interesting stories, and the technological wizardry and international diplomacy that helped shape the roots of our digital audio visual world are worth looking into.

In 1976, when the green shoots of digital audio technology were emerging at industry level, the question of whether Video Tape Recorders (VTRs) could be digitised began to be explored in earnest by R & D departments based at SONY, Ampex and Bosch G.m.b.H. There was considerable scepticism among researchers about whether digital video tape technology could be developed at all because of the wide frequency required to transmit a digital image.

In 1977 however, as reported on the SONY websiteYoshitaka Hashimoto and team began to intensely research digital VTRs and 'in just a year and a half, a digital image was played back on a VTR.'

Several years of product development followed, shaped, in part, by competing regional preferences. As Jim Slater argues in Modern Television Systems (1991): 'much of the initial work towards digital standardisation was concerned with trying to find ways of coping with the three very different colour subcarrier frequencies used in NTSC, SECAM and PAL systems, and a lot of time and effort was spent on this' (114).

Establishing a standard sampling frequency did of course have real financial consequences, it could not be randomly plucked out the air: the higher the sampling frequency, the greater overall bit rate; the greater overall bit rate, the more need for storage space in digital equipment. In 1982, after several years of negotiations, a 13.5 MHz sampling frequency was agreed. European, North American, 'Japanese, the Russians, and various other broadcasting organisations supported the proposals, and the various parameters were adopted as a world standard, Recommendation 601 [a.k.a. 4:2:2 DTV] standard of the CCIR [Consultative Committee for International Radio, now International Telecommunication Union]' (Slater, 116).

The 4:4:2 DTV was an international standard that would form the basis of the (almost) exclusively digital media environment we live in today. It was 'developed in a remarkably short time, considering its pioneering scope, as the worldwide television community recognised the urgent need for a solid basis for the development of an all-digital television production system', write Stanley Baron and David Wood

Once agreed upon, product development could proceed. The first digital video tape, the D-1, was introduced on the market in 1986. It was an uncompressed component video which used enormous bandwidth for its time: 173 Mbit/sec (bit rate), with maximum recording time of 94 minutes.

large cream-coloured video machine with electroluminescent display panel

BTS DCR 500 D-1 video recorder at Greatbear studio

As Slater writes: 'unfortunately these machines are very complex, difficult to manufacture, and therefore very expensive […] they also suffer from the disadvantage that being component machines, requiring luminance and colour-difference signals at input and output, they are difficult to install in a standard studio which has been built to deal with composite PAL signals. Indeed, to make full use of the D-1 format the whole studio distribution system must be replaced, at considerable expense' (125).

Being forced to effectively re-wire whole studios, and the considerable risk involved in doing this because of continual technological change, strikes a chord with the challenges UK broadcast companies face as they finally become 'tapeless' in October 2014 as part of the Digital Production Partnership's AS-11 policy.

Sequels and product development

As the story so often goes, D-1 would soon be followed by D-2. Those that did make the transition to D-1 were probably kicking themselves, and you can only speculate the amount of back injuries sustained getting the machines in the studio (from experience we can tell you they are huge and very heavy!)

It was fairly inevitable a sequel would be developed because even as the D-1 provided uncompromising image quality, it was most certainly an unwieldy format, apparent from its gigantic size and component wiring. In response a composite digital video, the D-2, was developed by Ampex and introduced in 1988.

In this 1988 promotional video, you can see the D-2 in action. Amazingly for our eyes and ears today the D-2 is presented as the ideal archival format. Amazing for its physical size (hardly inconspicuous on the storage shelf!) but also because it used composite video signal technology. Composite signals combine on one wire all the component parts which make up a video signal: chrominance (colour, or Red Green, Blue - RGB) and luminance (the brightness or black and white information, including grayscale).

While the composite video signal used lower bandwidth and was more compatible with existing analogue systems used in the broadcast industry of the time, its value as an archival format is questionable. A comparable process for the storage we use today would be to add compression to a file in order to save file space and create access copies. While this is useful in the short term it does risk compromising file authenticity and quality in the long term. The Ampex video is fun to watch however, and you get a real sense of how big the tapes were and the practical impact this would have had on the amount of time it took to produce TV programmes.

Enter the D-3

Following the D-2 is the D-3, which is the final video tape covered in this article (although there were of course the D5 and D9.)

The D-3 was introduced by Panasonic in 1991 in order to compete with Ampex's D-2. It has the same sampling rate as the D-2 with the main difference being the smaller shell size.

The D-3's biggest claim to fame was that it was the archival digital video tape of choice for the BBC, who migrated their analogue video tape collections to the format in the early 1990s. One can only speculate that the decision to take the archival plunge with the D-3 was a calculated risk: it appeared to be a stable-ish technology (it wasn't a first generation technology and the difference between D-2 and D-3 is negligible).

The extent of the D-3 archive is documented in a white paper published in 2008, D3 Preservation File Format, written by Philip de Nier and Phil Tudor: 'the BBC Archive has around 315,000 D-3 tapes in the archive, which hold around 362,000 programme items. The D-3 tape format has become obsolete and in 2007 the D-3 Preservation Project was started with the goal to transfer the material from the D-3 tapes onto file-based storage.'

Tom Heritage, reporting on the development of the D3 preservation project in 2013/2014, reveals that 'so far, around 100,000 D3 and 125,000 DigiBeta videotapes have been ingested representing about 15 Petabytes of content (single copy).'

It has then taken six years to migrate less than a third of the BBC's D-3 archive. Given that D-3 machines are now obsolete, it is more than questionable whether there are enough D-3 head hours left in existence to read all the information back clearly and to an archive standard. The archival headache is compounded by the fact that 'with a large proportion of the content held on LTO3 data tape [first introduced 2004, now on LTO-6], action will soon be required to migrate this to a new storage technology before these tapes become difficult to read.' With the much publicised collapse of the BBC's (DMI) digital media initiative in 2013, you'd have to very strong disposition to work in the BBC's audio visual archive department.

The roots of the audio visual digital world

The development of digital video tape, and the international standards which accompanied its evolution, is an interesting place to start understanding our current media environment. They are also a great place to begin examining the problems of digital archiving, particularly when file migration has become embedded within organisational data management policy, and data collections are growing exponentially.

While the D-1 may look like an alien-techno species from a distant land compared with the modest, immaterial file lists neatly stored on hard drives that we are accustomed to, they are related through the 4:2:2 sample rate which revolutionised high-end digital video production and continues to shape our mediated perceptions.

Preserving early digital video formats

More more information on transferring D-1, D-2, D3, D-5, D-5HD & D-9 / Digital S from tape to digital files, visit our digitising pages for:

D-1 (Sony) component and D-2 (Ampex) composite 19mm digital video cassettes

Composite digital D-3 and uncompressed component digital D-5 and D-5HD (Panasonic) video cassettes

D-9 / Digital S (JVC) video cassettes

Posted by debra in video tape, video technology, machines, equipment, 7 comments

Future tape archaeology: speculations on the emulation of analogue environments

At the recent Keeping Tracks symposium held at the British Library, AV scoping analyst Adam Tovell stated that

‘there is consensus internationally that we as archivists have a 10-20 year window of opportunity in which to migrate the content of our physical sound collections to stable digital files. After the end of this 10-20 year window, general consensus is that the risks faced by physical media mean that migration will either become impossible or partial or just too expensive.’

This point of view certainly corresponds to our experience at Greatbear. As collectors of a range of domestic and professional video and audio tape playback machines, we are aware of the particular problems posed by machine obsolescence. Replacement parts can be hard to come by, and the engineering expertise needed to fix machines is becoming esoteric wisdom. Tape degradation is of course a problem too. These combined factors influence the shortened horizon of magnetic tape-based media.

All may not be lost, however, if we are take heart from a recent article which reported the development of an exciting technology that will enable memory institutions to recover recordings made over 125 years ago on mouldy wax cylinders or acid-leaching lacquer discs.

IRENE (Image, Reconstruct, Erase Noise, Etc.), developed by physicist Carl Haber at the Lawrence Berkeley National Laboratory, is a software programme that ‘photographs the grooves in fragile or decayed recordings, stitches the “sounds” together with software into an unblemished image file, and reconstructs the “untouchable” recording by converting the images into an audio file.’

The programme was developed by Haber after he heard a radio show discuss the Library of Congress’ audio collections that were so fragile they risked destruction if played back. Haber speculated that the insights gained from a project he was working on could be used to recover these audio recordings. ‘“We were measuring silicon, why couldn’t we measure the surface of a record? The grooves at every point and amplitude on a cylinder or disc could be mapped with our digital imaging suite, then converted to sound.”’

For those involved in the development of IRENE, there was a strong emphasis on the benefits of patience and placing trust in the inevitable restorative power of technology. ‘It’s ironic that as we put more time between us and the history we are exploring, technology allows us to learn more than if we had acted earlier.’

Can such a hands-off approach be applied to magnetic tape based media? Is the 10-20 year window of opportunity described by Tovell above unnecessarily short? After all, it is still possible to playback wax cylinder recordings from the early 20th century which seem to survive well over long periods of time, and magnetic tape is far more durable than is commonly perceived.

In a fascinating audio recording made for the Pitt Rivers Museum in Oxford, Nigel Bewley from the British Library describes how he migrated wax cylinder recordings that were made by Evans Pritchard in 1928-1930 and Diamond Jenness in 1911-1912. Although Bewley reveals his frustration in the preparation process, he reveals that once he had established the size of stylus and rotational speed of the cylinder player, the transfer was relatively straightforward.

You will note that in contrast with the recovery work made possible by IRENE, the cylinder transfer was made using an appropriate playback mechanism, examples of which can accessed on this amazing section of the British Library’s website (here you can also browse through images and information about disc cutters, magnetic recorders, radios, record players, CD players and accessories such as needle tins and headphones – a bit of a treasure trove for those inclined toward media archaeology).

Perhaps the development of the IRENE technology will mean that it will no longer be necessary to use such ‘authentic’ playback mechanisms to recover information stored on obsolete media. This brings us neatly to the question of emulation.

Emulation

Insides of a beta-hi-fi machine

If we assume that all the machines that play back magnetic tape become irrevocably obsolete in 10-20 years, what other potential extraction methods may be available? Is it possible that emulation techniques, commonly used in the preservation of born-digital environments, can be applied to recover the recorded information stored on magnetic tape?

In a recent interview Dirk Von Suchodoletz explains that:

‘Emulation is a concept in digital preservation to keep things, especially hardware architectures, as they were. As the hardware itself might not be preservable as a physical entity it could be very well preserved in its software reproduction. […] For memory institutions old digital artifacts become more easy to handle. They can be viewed, rendered and interacted-with in their original environments and do not need to be adapted to our modern ones, saving the risk of modifying some of the artifact’s significant properties in an unwanted way. Instead of trying to mass-migrate every object in the institution’s holdings, objects are to be handled on access request only, significantly shifting the preservation efforts.’

For the sake of speculation, let us imagine we are future archaeologists and consider some of the issues that may arise when seeking to emulate the operating environments of analogue-based tape media.

To begin with, without a working transport mechanism which facilitates the transmission of information, the emulation of analogue environments will need to establish a circuitry that can process the Radio Frequency (RF) signals recorded on magnetic tape. As Jonathan Sterne reflects, ‘if […] we say we have to preserve all aspects of the platform in order to get at the historicity of the media practice, that means archival practice will have to have a whole new engineering dimension to it.’

Yet with the emulation of analogue environments, engineering may have to be a practical consideration rather than an archival one. For example, some kind of transport mechanism would presumably have to be emulated through which the tape could be passed through. It would be tricky to lay the tape out flat and take samples of information from its surface, as IRENE’s software does to grooved media, because of the sheer length of tape when it unwound. Without an emulated transport mechanism, recovery would be time consuming and therefore costly, a point that Tovell intimates at the beginning of the article. Furthermore, added time and costs would necessitate even more complex selection and appraisal decisions on behalf of archivists managing in-operative magnetic tape-based collections. Questions about value will become fraught and most probably politically loaded. With an emulated transport mechanism, issues such as tape vulnerability and head clogs, which of course impact on current migration practices, would come into play.

Audio and video differences

On a technical level emulation may be vastly more achievable for audio where the signal is recorded using a longitudinal method and plays back via a relatively simple process. Audio tape is also far less propriety than video tape. On the SONY APR-5003V machine we use in the Greatbear Studio for example, it is possible to play back tapes of different sizes, speeds, brands, and track formations via adjustments of the playback heads. Such versatility would of course need to be replicated in any emulation environment.

helical scan The technical circuitry for playing back video tape, however, poses significantly more problems. Alongside the helical scan methods, which records images diagonally across the video tape in order to prevent the appearance of visible joints between the signal segments, there are several heads used to read the components of the video signal: the image (video), audio and control (synch) track.

Unlike audio, video tape circuitry is more propriety and therefore far less inter-operable. You can’t play a VHS tape on a U-Matic machine, for example. Numerous mechanical infrastructures would therefore need to be devised which correspond with the relevant operating environments – one size fits all would (presumably) not be possible.

A generic emulated analogue video tape circuit may be created, but this would only capture part of the recorded signal (which, as we have explored elsewhere on the blog, may be all we can hope for in the transmission process). If such systems are to be developed it is surely imperative that action is taken now while hardware is operative and living knowledge can be drawn upon in order to construct emulated environments in the most accurate form possible.

While hope may rest in technology’s infinite capacity to take care of itself in the end, excavating information stored on magnetic tape presents far more significant challenges when compared with recordings on grooved media. There is far more to tape’s analogue (and digital) circuit than a needle oscillating against a grooved inscription on wax, lacquer or vinyl.

The latter part of this article has of course been purely speculative. It would be fascinating to learn about projects attempting to emulate the analogue environment in software – please let us know if you are involved in anything in the comments below.

Posted by debra in audio tape, audio technology, machines, equipment, video tape, video technology, machines, equipment, 0 comments

Transfer Digital Betacam (DigiBeta) to Quicktime or AVI now, one day they will be obsolete

Even relatively recent born-digital formats like Digital Betacam (or DigiBeta, as it’s often referred to) should be viewed as a potentially obsolete format. This Standard Definition (SD) format while very popular for many years is not the preferred delivery format now the industry has embraced High Definition (HD).

When serviced these machines are very reliable and would be worked hard in a production environment. Designed to be serviced with little expense spared these were some of Sony’s most expensive decks and even if second hand values of machines have dropped recently, new spares have not. As with most video formats though as they become less popular the spares availability will become a problem as parts inventory dry up. One day and it may not be that far away a popular format like DigiBeta will become a threatened, obsolete format.

Digibeta_close up right angle

Digital Betacam recorders  were introduced in 1993, superseding the Betacam and Betacam SP, while costing significantly less, and being dramatically smaller than (!), the D-1.

We are particularly pleased with this machine because there are relatively low hours on its original head drum (1000 hours). The average headlife for this format is up to three times that or more, depending on the environment it was used in.

If the machine was used in a heavy production environment, for example, it would be constantly drawing in air to cool the electronics and, potentially, large amounts of dust and debris with it. This is one of the factors affecting head life.

Part of the service kit installed on the DigiBeta is designed to counter such damage because it allows you to replace the filters around the head drum area should they become clogged.

dvw-a510-digital-betacam-loading-gear

The big problem, as with so many of these machines, is acquiring relevant parts to ensure they can be serviced when they break down. Spare parts for DigiBeta machines can be expensive, costing several thousand pounds for a replacement head drum.

This machine has needed some work recently to keep it running smoothly. The loading gear had split which meant it couldn’t load tapes and gave reel motor errors. These were fixed easily by replacing the broken parts. After these repairs were completed the picture was still however displaying errors. This was because the bearing on the pinch roller was worn resulting in too much movement in the tape path. With the problem diagnosed a new pinch roller was installed and our new machine is working beautifully!

So send us your DigiBeta tapes!

Posted by debra in video tape, video technology, machines, equipment, 0 comments

D-1 digital video transfer – new additions and economies of size

A recent addition to the Greatear digitising studio is a BTS D-1 digital video cassette recorder.

As revolutionary as it was at the time, early digital audio and video tape recording is more threatened with obsolescence than earlier analogue formats.

bts-dcr-300-d1-digital-video-recorder

Introduced in 1986, D-1 was the very first, real-time, digital broadcast-quality tape format. It stored uncompressed digitized component video, had uncompromising picture quality and used enormous bandwidth for its time. The maximum record time on a D-1 tape is 94 minutes.

Enormous is certainly the word for the D-1 tape! Compared with the so-called ‘invisible’ nature of today’s digital data and the miniDV introduced in 1998, this tape from 1992 is in comedy proportions.

d1-minidv-tape-comparison-2

D-1 was notoriously expensive and the equipment required large infrastructure changes in facilities which upgraded to this digital recording format.

Early D-1 operations were plagued with difficulties, though the format quickly stabilized and is still renowned for its superb standard definition image quality, sometimes referred to as a ‘no compromise’ format.

D-1 kept the data recorded as uncompressed 8bit 4:2:2, unlike today where compression is required for digital data to save space and time for practical delivery to the home, but sacrificing the picture and sound quality in the process.

D1 was supplanted by subsequent D models that recorded component (D-5) and composite (D-2 and D-3) signals.

Read more about digitising D-1 (Sony) component and D-2 (Ampex) composite 19mm digital video cassettes and D-3 composite and D-5 uncompressed component (Panasonic) digital video cassettes on our project pages.

Posted by debra in video tape, video technology, machines, equipment, 1 comment

V2000 bad Frako capacitor in Grundig 2×4 Video 2000

Video 2000 Frako X2 capacitor in Grundig 2x4

Yet again bad capacitors have reared their electrolytic fluid! This time in a Grundig Video 2000 video tape player, or V2000.

Pictured above is a X2 mains film cap in the power supply of the video machine, made by Frako. This brand of capacitors are German and used in many Studer audio tape machines too which commonly have similar smoking fun such as the B67 and sometimes the A80.

A nice satisfying repair though – all Frako film and electrolytic capacitors were desoldered and replaced with 105 degrees rated Panasonics. The circuit boards on these type of machines are also well made with thick tracks so there’s little risk of lifting solder pads with this type of repair.

Other than their ageing capacitors and some dry solder joint problems these Grundig machines are excellent although as with many older domestic formats the important proprietory spares like the V2000 upper head drums are very rare new now so keeping these machines running will get harder and more expensive over time.

It’s a good idea to digitise and transfer any video recordings on formats like Video 2000 to file based digital formats or at the very least DVD sooner rather than later.

Posted by greatbear in video tape, video technology, machines, equipment, 2 comments

Video time base corrector self destructing mains socket

Filtered mains socket self destructs in CEL TBC

We have several time base correctors and frame synchronisers at our disposal. One recent addition is a new old stock (NOS) CEL Tetra. This is an early 1990s motion adaptive Standards Converter for PAL, SECAM, NTSC 3.58 and NTSC 4.43 systems. A very flexible unit with composite, Y/C (S-Video), U-matic DUB High Band/Low Band and component inputs and outputs.

Out unit still has its shipping caps over the BNC sockets and looks unused but after 5 minutes of power a cloud of white smoke billowed out of the cooling fan accompanied by a pungent smell. The Shaffner EMI mains filter had a nasty, sticky brown residue leaking out and all around the back of it. This is the second TBC that I’ve had this happen to. I’d assumed these units get left on for long periods when used in broadcast applications which would hasten their demise. According to their website, the mean time between failures (MTBF) of their recent products is around 2,000,000 hours! Our CEL TBC doesn’t look like it’s done more than 30 minutes so maybe there’s been some dodgy electrolytic fluid in these units just like the motherboard capacitor problems between 2000 and 2003.

Posted by greatbear in video tape, video technology, machines, equipment, 1 comment

Switch mode power supply (SMPSU) repair in For-a FA-310P time base corrector

For-a FA310P Switch Mode Power Supply

We use time base correctors and frame synchronizers all the time in the transfer and digitising of analogue video tape.

One of our more flexible and high quality units had recently developed an annoying and very obvious fault on its video outputs. While the unit was working there were faint but distinct horizontal lines on the video. This phenomenon is often called a hum bar and can be caused by ground loops.

In this case we isolated the unit from the rest of our installation and using a separate power point the problem was still there. Looking at the unit itself it is a very deep and heavy 1U case with two 40mm cooling fans at the rear corners. It is quite old too and being designed for continuous studio use is likely to get hot and have been on for very long periods.

The video fault appeared to be AC ripple ‘riding’ on the DC power. It was time to look at the electrolytic capacitors in the power supply.

Although I could have tested each one, all these caps were old and only rated for 3000 hrs at 85 celcius so they all had to go! Here’s a list of them:

The only one hard to find was the large 400v dump one. Most units now are thinner and taller but eBay came to rescue here.

This shotgun approach worked beautifully and the fault had gone. While tracing the exact fault is always the best way, capacitor often get a hard life and will not last indefinitely, especially in switch mode power supplies.

Posted by greatbear in video tape, video technology, machines, equipment, 1 comment

JVC PV-4800E 1/2 inch EIAJ colour portable video recorder

jvc_pv_4800e_reel_to_reel_colour_video_recorder

A recent addition to our video arsenal is this rare 1976 vintage 1/2″ colour reel to reel machine.

This has needed some work to get it functioning well such as new belts, hardened grease cleaned off the mechanism, etc but is now able to transfer colour recordings made in this format of reel to reel video.

A more detailed article on the repair of this will appear soon as will information about our other reel to reel video machines, the Hitachi / Shibaden EIAJ machine, the Sony CV-2100 skip field VTR and the enormous Ampex VPR-2B 1″ video machine… and we’ve got two of these!

Thanks to Rich at www.labguysworld.com for the JVC service manuals.

Posted by greatbear in video tape, video technology, machines, equipment, 0 comments