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back to article Video thrilled the radio star: Tracking the history of magnetic tape

El Reg's magnetic tape odyssey has covered tape's early beginnings in sound recording in part one and its revolution in computing in part two. In this final part, we look at how film and TV became some of magnetic tape's best customers. The music and computer industries weren’t the only early adopters of magnetic tape. The …

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Quadraplex

Quadraplex or simply 2 inch as it's known in the trade had a tape format service life that is astonishing. The BBC were using it on a day to day basis until C Format was adopted around 1983. 2 inch was still in use though to play back older shows and had a day to day service life of around 30 years! Even then some machines remained for archive footage and the last machine was only taken out of TV Centre about 5 or 6 years ago.

It hung on longer as a main format of choice at other places and the Beeb even sold off some of their machines to foreign broadcasters where they were still being used in the late 90's!

For those interested in the history of VT at the BBC visit here - http://www.vtoldboys.com

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Tip for cheap, long digital audio recording - think DJ sets, parties etc.

Snag yourself a Nicam Digital Stereo VHS machine on ebay and stick a 4hour tape in.

Just use the audio inputs and forget the video input, unless you're on the mixing desk, then why not plug in a camera as well, and you have something ready for YouTube.

I believe the audio quality is the same if you use LP and EP to get 8hour, or longer, recordings.

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Re: Tip for cheap, long digital audio recording - think DJ sets, parties etc.

Radio stations used to use this technique to create the log tapes they were required to hold for 42 days until such time as hard disk recording became feasible/cheap.

Word of warning about LP and EP. While the sound quality remains the same, the slower the tape runs the harder it can be to get good playback and the more drop out you'll get. I have loggers from my radio days that can prove problematic in some VCR's.

Also be sure you aren't hitting the audio limiters in the VCR. If you can get one that gives a visual of the audio inputs then that is useful.

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Re: Tip for cheap, long digital audio recording - think DJ sets, parties etc.

Just googled the Nicam specs, and as well as the digital stereo recorded diagonally, there is also a linear analogue copy along the edge of the tape - a built in backup for compatibility with non-Nicam players.

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Anonymous Coward

Re: Tip for cheap, long digital audio recording - think DJ sets, parties etc.

NICAM was the over-the-air format that was used to transmit digital audio on TV, on a separate carrier from the video and analogue mono sound ones. It wasn't part of the recording process, just the broadcast delivery.

The HiFi VHS sound recording system was very much an analogue affair, using the helical heads, FM carriers, etc - and sometimes vulnerable to audible artifacts of the head switching and companding system used.

But it was extremely impressive in its time.

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Anonymous Coward

Just thank you ..

.. for another nice glimpse into history. I can recall the tape libraries used by Sky TV before they went digital, which was a fun sight in itself.

BTW,

one format over another would give the adult entertainer an easy ride

I saw what you did there :)

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Curious thing...

The Philips V2000 format that no-one remembers was technically the best of the three at the time - ignoring the turn-over tape, it had active track following (using a couple of audio subcarriers laid down at the same time as the video) that meant slow-speed and stationary images were possible with no noise bars.

The way the Betamax and C format did track following was a lot more complex, I suspect to avoid paying any royalties to Philips - Sony were famous for building a PAL decoder that looked at the inter-field pulses to avoid the patent on the swinging burst decoder...

C Hill's comments take me back to days of being bollocked for forgetting to change the legal recorder tape!

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Re: Curious thing...

Well Video 2000, which was a joint development of Grundig and Philips, had it's own load of problems. Certain models were badly designed with cheap plastic connectors breaking off causing the machine to go into "self destruct" mode.

Of course then the tape, particularly the 2x4/2x8 tapes were incredibly thin and tended to stretch unevenly.

The trick play of Vido2000 was rather well, unfortunately the transport wasn't good enough to actually make use of it. If they had stepped back on recording length and just had improved the quality and reliability, they would have had a nifty format spanning a wide range of uses from the sophisticated amateur to the odd professional use.

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Magnetic media

An interesting series of articles!

How about one on magnetic data media next? Floppy and hard disks etc.

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Thumb Up

Thanks El Reg

I've really enjoyed this series of articles.

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Bad joke warning

Esteemed Author» Shall we talk about porn? While there’s no hard evidence per se,...

I would've thought that there was lots of hard evidence, but maybe that's just me.

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Bendy heads

As I recall with a helical head wrap you don't get a straight track, but a skewed, S-shape one. Heads mounted on the drum needed to bend to read/write the tracks effectively

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Re: Bendy heads

If the servo is working as it should the track is perfectly straight - used to make alignment tapes part of the process of setting up the master recorder involved taking a length of tape and "developing" using a fero-fluid.

The straightness of the tacks - spacing etc. was then measured to a fraction of a micron using a high power measuring Microscope, logging the x.y coordinates of 50 or so points down a few stripes. This was then fed to a Maths cad program to calculate how straight the tracks where etc.

Not a quick process, took an hour or so – not forgetting if wrong it was back adjusting the inlet/outlet guides etc, hence why good alignment tapes are so expensive.

( commercial VHS alignment tapes were like bananas in comparison, but still sufficient to set-up domestic VCR’s)

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Happy

many thankings from an old and unapologetic tapehead

This series has been a fun trip down memory lane, while teaching me some things I didn't know missed along the way.

More of this sort of thing El Regarding, I know you can do it.

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Daft Punk

Was sitting here listening to Daft Punk's Random Access Memories, when I paused to watch the video of Philips' VCR 2000 video. I'll be damned if the background music didn't sound like Daft Punk!

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VHS vs. Beta....

One of the reasons that VHS won out over beta was that its recording time in normal (1x) mode was two hours. Given that number, you could put a nice movie on a SINGLE tape.

By the time Beta increased its playing time, VHS had movies lined up and working.

The marvel of the helical scan boxes (U-Matic, Beta, VHS) was the mechanics involved in "threading" the tape. You open up a U-Matic machine and watch it go through its threading and it is a wonder to behold.

The nice 3/4 inch U-Matic machine I've got is somewhere in the garage. I believe it still is operational for NTSC signals. I'll need to plug it in to make sure. Such fun! The nice thing about that machine (it is a JVC one as I recall) was that it could video process sync signals very nicely and re-record those pesky "copy protected" tapes I got from the video store.

But life goes on, and now the TiVo box does most of the recording now.

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Great article

As with your previous articles on tape this has been an interesting and fantastic read

One the about VHS though. For years now I believed that VHS stood for Vertical Helical Scanning, and it would appear that Wikipedia agrees with the article and calls it Video Home System. But I do remember speaking to a JVC rep back in the mid eighties who definitely referred to it as Vertical Helical Scanning.

Ok, after a bit of research it would appear that JVC's original intention was to call it Video Home System, but for some reason in Europe "Vertical Helical Scan" was often used in place of "Video Home System" despite it being incorrect, not least for the fact that if it was to do with the technology it should have been called DHS - Diagonal Helical Scan.

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Dolby film fun.

Anyone notice the lovely touch of the Double D logo in the middle of the Dolby Digital digital encoding - try reverse engineering that without a trademark issue.

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mellotron?

Great series- am a bit suprised the quirky keyboard instrument known as the Mellotron was not mentioned. All of its sounds were played back from tape samples and gave us much to listen to from the 60's and '70s bands.

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Re: mellotron?

To be fair, such a digression could easily fill another 3-4 articles on its own.

Magnetic recording triggered the birth of the technique many (incorrectly) refer to as "sampling" today. (The term is "sample loops" or just "loops" – "sampling" refers to the process of recording the actual sounds digitally.) The looping of those sampled sounds underly almost all music today. It's most obvious in the work of Norman Cook, but even 'live' acts use it as a matter of routine now in their studio recordings.

This technique was first used in the 1940s and led directly to the "Musique Concrète" movement that was so influential on the likes of the BBC Radiophonic Workshop. Most of their output during the 1950s and '60s was Musique Concrète, albeit often with very early synthesised sounds added.

The term "loop" came from these pioneers: they had to do it the hard way, by recording sounds onto tape, re-recording them as many times as required onto another tape – at different speeds, in order to get the necessary notes – then chopping the resulting tape up into individual notes. (This was all worked out mathematically, hence the maths or engineering backgrounds of many of those involved.)

These individual snippets of sound – bass lines, rhythm / percussion cycles, even short sections of melody – were then joined together to form the necessary tape loops needed to produce the final piece. For example, the percussion sequence might be quite short and result in a fairly short loop of tape that could be repeated over the full track. (Most music is filled with repeated patterns and motifs. Listen to any dance track and it's pretty obvious, but you'll hear it even in Beethoven and Bach.)

A complex piece might require multiple, very long, loops of tape, all played in synchrony, with some loops so long that the team would have to jerry-rig a system of reels and pulleys to run the tape out of the machine, out of the door, down a corridor, and all the way back again.

Multiple tape machines were used for this. Even "bouncing" tracks is a term descended from this era.

Digital audio workstations ("DAWs") hide all the fiddly mathematics and tape editing today, but the underlying concepts and principles haven't changed.

Most of this can be gleaned from the BBC's own (belated) celebration of the defunct BBC Radiophonic Workshop: The Alchemists of Sound It's a shame the BBC never expanded it into a series covering the wider context of electronic music in general.

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Anonymous Coward

Optical tracks

Actually there were 2 types of competing optical sound tracks. Your pictures show RCA's variable area system, not the Western Electric variable density system mentioned in the text. RCA's system, because silence meant a very narrow transparent stripe, had a claimed improved SNR over variable density.

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Pint

thank you

great series; please continue.

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Great series

Thanks.

Perhaps as a follow-up one on how data is restored from degraded tape? With Patrick Troughton DW in the news I'd love to know how they make old telly sparkle.

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A Video mellotron?

Back in the early 70s (71 IIRC) I witnessed a demo of what was a video combination of a Mellotron and a cart marchine (as used for playing radio jingles).

It was made by Ampex, used 2inch tape and was designed for commercial TV stations so that the content of advert breaks could be altered at will and at the last minute.

Individual ads were stored on tape in a small box akin to an audio cart. Except that they were bigger (they had 2inch tape in them) and the tape was stored as a single strip loose in a wave (there was no spool IIRC) with one end of the tape poking out of a slot in the side of the box. I can't remember if the tape rested on its edge or was layed flat - it's a long time ago, but logic suggests that it would stand on its edge for the wave to work better.

The boxes were loaded up into the machine prior to the commercial break in the sequence they were to be played. At the required time the machine went into action and the first two ads were loaded up ready to play.

This was rather clever, The tape was extracted from its box and laced up pneumatically, ready to play on cue, with the second tape loaded ready to play on the end cue of tape one (there were two seperate playback mechanisms - I should have said that earlier).

While tape 2 was playing, tape 1 was magically sucked (or blown) back into its box, shuffled out of the way and tape 3 moved into position ready for its sucking lace-up and cuing. - and so on until the end of the ad break.

The 'carts' could be resequenced right up to going on air.

I may be wrong about the wave storage - there could have been a spring-loaded rewind reel in the box but I don't remember that there was.

I seem to recall thinking that the possibilty of this going seriously wrong was quite high as there was so much going on and loose tape was involved.

I don't know if any were sold as I never saw one again. (and it was a big beast!)

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Re: A Video mellotron?

You are probably talking about an RCT TCR-100. Yes those were sold to stations.

Here's a video of one in action:

http://www.youtube.com/watch?v=_YhuUVzg8Dg

And here's a video of people collecting such machines:

http://www.youtube.com/watch?v=hGI-cMqSf-g

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Re: A Video mellotron?

Actually this was it.

http://www.youtube.com/watch?v=m_YXCNpTfAg

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Re: A Video mellotron?

Ah yes, there were several of those machines. In fact even today you can get tape robots for your VCRs.

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