1 00:00:01,299 --> 00:00:06,264 [Door opens, footsteps] 2 00:00:06,265 --> 00:01:08,086 [Jazzy music: 'The Russians Are Coming' - Val Bennett] 3 00:01:08,087 --> 00:01:12,180 [music fades out] [clanking, pneumatic hissing noises] 4 00:01:12,181 --> 00:01:17,067 Tim: Something bizarre like this set which Rex and I were working on last year is obviously an illusion. 5 00:01:17,068 --> 00:01:21,349 But in fact me and everything else on television is really just as much of an illusion. 6 00:01:21,350 --> 00:01:26,451 While you're sitting at home watching this programme, I'll probably be sitting at home watching it too. 7 00:01:26,452 --> 00:01:31,418 What you're actually looking at is an elaborate illusion created by a reel of video tape. 8 00:01:32,121 --> 00:01:37,351 The video recorder, like the other machines in this series, has become quite indispensable, 9 00:01:37,352 --> 00:01:40,315 yet very few people have any idea how the thing works. 10 00:01:40,316 --> 00:01:43,839 In this programme, Rex and I are going to try and demystify it a bit. 11 00:01:44,572 --> 00:01:47,513 [clank of lid] 12 00:01:47,514 --> 00:01:49,723 Inside, it does look quite baffling. 13 00:01:49,724 --> 00:01:53,647 One half is full of a mass of electronics and circuit boards. 14 00:01:53,648 --> 00:01:56,623 And the other half where the cassette goes in, is full of 15 00:01:56,624 --> 00:02:00,914 equally baffling mechanisms, gears and pulleys and things. 16 00:02:00,915 --> 00:02:05,740 But despite all this complexity, the basic principles of magnetic recording are really very simple. 17 00:02:05,741 --> 00:02:09,571 They were first developed nearly 100 years ago for recording sound. 18 00:02:10,778 --> 00:02:13,922 A Danish telephone engineer called Valdemar Pullson, 19 00:02:13,923 --> 00:02:16,348 convinced that there was a need for a permanent record 20 00:02:16,349 --> 00:02:19,011 of business transactions conducted by telephone. 21 00:02:19,012 --> 00:02:22,688 Started experimenting with magnetic recording in 1896. 22 00:02:25,473 --> 00:02:29,265 Pullson had found he could magnetise a bit of steel... 23 00:02:29,266 --> 00:02:37,032 [magnet clicks against table] 24 00:02:37,067 --> 00:02:44,145 And then see exactly where he'd magnetised it by dipping it in some iron filings. 25 00:02:48,743 --> 00:02:53,115 He could magnetise the steel in just the same way with an electromagnet, 26 00:02:53,116 --> 00:02:56,198 this is just a coil of wire wrapped round a lump of steel. 27 00:02:57,018 --> 00:02:59,979 But he could also use the electromagnet like the iron filings 28 00:02:59,980 --> 00:03:02,131 to see where he'd magnetised it. 29 00:03:02,132 --> 00:03:05,561 I've connected this electromagnet to a meter here. 30 00:03:05,562 --> 00:03:11,487 And erm, if I bring a permanent magnet anywhere near it... 31 00:03:11,488 --> 00:03:14,100 I think you can see the meter move. 32 00:03:14,101 --> 00:03:16,417 It's actually creating some electricity. 33 00:03:16,418 --> 00:03:21,756 So if I now pass the er, electromagnet along the strip of steel. 34 00:03:23,150 --> 00:03:26,938 You can see it moves, at the point where I magnetised it earlier. 35 00:03:26,939 --> 00:03:32,430 This may seem surprising, but the properties of electricity and magnetism are intimately connected. 36 00:03:33,819 --> 00:03:39,337 Well now I can use the endless loop of steel of my bandsaw... 37 00:03:39,338 --> 00:03:42,413 [horribe grinding noise] 38 00:03:42,414 --> 00:03:46,014 To make the bandsaw into a primitive tape recorder. 39 00:03:46,865 --> 00:03:50,829 First I've got to connect the whole thing up. 40 00:03:50,830 --> 00:03:53,034 To a battery and a switch. 41 00:03:57,539 --> 00:04:02,969 Well now I can magnetise a few places of the, on the steel strip. 42 00:04:02,970 --> 00:04:06,394 Or, in other words, record a few magnetic pulses... 43 00:04:06,395 --> 00:04:17,670 [bandsaw grinding noise] 44 00:04:19,250 --> 00:04:22,888 And now I can see where I have magnetised it on the strip, simply by 45 00:04:22,889 --> 00:04:26,890 continuing to run, in other words I'm playing the signal back. 46 00:04:26,891 --> 00:04:38,117 [bandsaw grinds] 47 00:04:38,118 --> 00:04:41,895 This is the basic principle of magnetic recording, and it's 48 00:04:41,896 --> 00:04:45,334 just the same on the most sophisticated modern video recorder. 49 00:04:45,335 --> 00:04:48,375 The heart of the machine is this spinning drum. 50 00:04:48,376 --> 00:04:51,495 Underneath if I undo this screw... 51 00:05:01,445 --> 00:05:04,595 This is the actual tape head. 52 00:05:04,596 --> 00:05:06,983 And you can see its tiny coil of wire. 53 00:05:06,984 --> 00:05:11,828 It's an electromagnet, and it's doing exactly the same thing as the electromagnet on the band saw. 54 00:05:12,800 --> 00:05:16,913 Well without all this sophistication, Pullsen had enormous difficulty 55 00:05:16,914 --> 00:05:20,725 recording the tiny electrical signals he was picking up from the telephone. 56 00:05:20,726 --> 00:05:24,281 However, he applied for patents all over the world, 57 00:05:24,282 --> 00:05:26,462 and found eager backers in America. 58 00:05:26,463 --> 00:05:28,200 Pullson: Hellooooo. 59 00:05:28,201 --> 00:05:34,899 Pullman: Now don't worry about the science. My invention is foolproof. All you need to know is you make lots of money. 60 00:05:34,900 --> 00:05:39,941 Men: *chatter* Great. It's a deal. Pullman: Thank you very much. 61 00:05:39,942 --> 00:05:45,299 Man: Okay Ladies and Gentlemen, this is your chance now to buy buy buy and make a fortune of a lifetime. 62 00:05:45,300 --> 00:05:47,227 Yes I'm talking about money. 63 00:05:47,228 --> 00:05:51,642 Tim: The backers were more interested in trading the stocks and shares than making telegrophones. 64 00:05:51,643 --> 00:05:55,467 But 7 years later, a saleable machine finally did appear, [Man babbles into telephone] 65 00:05:55,468 --> 00:05:57,705 advertised as a dictation system. 66 00:05:57,706 --> 00:06:03,892 Man: We have no option except to foreclose on this. Yours sincerely, Iron T Washbucket. 67 00:06:03,893 --> 00:06:06,815 Secretary: I'll type this up right away. 68 00:06:07,739 --> 00:06:11,264 [crackle] Secretary: Oh oh oh. I can't hear a thing! 69 00:06:11,265 --> 00:06:13,700 Secretary: It's impossible, no I can't! 70 00:06:13,701 --> 00:06:18,131 Man: Ohhh. I'll go back to doing things the old way! 71 00:06:18,132 --> 00:06:21,132 Business Man: ... Thursday 25th January, Secretary: ... Okay.. 72 00:06:21,133 --> 00:06:28,110 [rattly wheels] 73 00:06:28,111 --> 00:06:31,370 Tim: This is one of the science museum's wonderful stores. 74 00:06:31,371 --> 00:06:35,785 And this is one of the few surviving telegrophones. 75 00:06:36,772 --> 00:06:40,564 In a way it's quite like a modern tape recorder, with its two reels, 76 00:06:40,565 --> 00:06:42,940 and the tape head in the middle. 77 00:06:42,941 --> 00:06:48,733 This contains the tiny electromagnet that actually records on this fine steel wire. 78 00:06:50,263 --> 00:06:53,708 The trouble was though, that the sound it reproduced was 79 00:06:53,709 --> 00:06:57,317 really just too faint to be of any practical use at all. 80 00:06:57,950 --> 00:07:00,652 Rex and I had a go at making a working model of one of these 81 00:07:00,653 --> 00:07:02,769 and we couldn't hear anything through it at all. 82 00:07:03,310 --> 00:07:05,890 But the idea wasn't totally forgotten. 83 00:07:05,891 --> 00:07:09,574 And as valves and electronic amplifiers improved 84 00:07:09,575 --> 00:07:12,065 the idea became progressively more practical. 85 00:07:12,066 --> 00:07:15,822 Also a German Dr. Stille spend most of the 1920s 86 00:07:15,823 --> 00:07:20,222 methodically analysing the theoretical principles of magnetic recording. 87 00:07:20,223 --> 00:07:25,807 And eventually in conjunction with Marconi started producing massive machines like this. 88 00:07:25,808 --> 00:07:37,977 [motors whirr, forklift wheels squeak] 89 00:07:37,978 --> 00:07:42,059 This particular machine was bought by the BBC in 1933. 90 00:07:44,199 --> 00:07:47,161 The tape heads are up at the top here. 91 00:07:47,162 --> 00:07:51,820 And it uses this very fine, razor sharp, steel tape. 92 00:07:53,205 --> 00:07:58,031 It's all incredibly large because to get a good enough sound quality 93 00:07:58,032 --> 00:08:01,668 it has to run very very fast, so it uses up a lot of tape. 94 00:08:02,457 --> 00:08:07,790 Its high speed has some disadvantages; you had to keep the tape oiled - there's an oiler over here. 95 00:08:07,791 --> 00:08:11,567 And it was also quite dangerous, you had to keep well out of the way 96 00:08:11,568 --> 00:08:16,652 because if the tape broke, this razor sharp steel would fly all over the room. 97 00:08:19,740 --> 00:08:27,311 Recording on steel still has one specialist use, where heat resistance is important, in black box flight recorders. 98 00:08:27,312 --> 00:08:32,163 The boxes are actually orange, not black, and they're extremely strong and well insulated. 99 00:08:33,770 --> 00:08:37,675 Inside you can see the bright stainless steel wire being replayed. 100 00:08:37,676 --> 00:08:42,218 [quiet whirring noise] 101 00:08:42,219 --> 00:08:45,349 The recorder is connected to a computer, and it prints out 102 00:08:45,350 --> 00:08:48,749 the positions of rudder, elevators and other controls. 103 00:08:48,750 --> 00:08:53,288 On a modern jumbo jet, over 60 items are recorded. 104 00:08:56,561 --> 00:09:02,460 Experiments with plastic tape were started by the German magnetophone company in the 1930s. 105 00:09:02,461 --> 00:09:06,772 The tape's coated with a magnetic powder that actually records the signal. 106 00:09:06,773 --> 00:09:11,853 This powder is a sort of iron oxide, or rust, which is why the tape's always brown. 107 00:09:12,632 --> 00:09:18,295 Well we can make a primitive sort of recording tape using sticky tape, 108 00:09:18,296 --> 00:09:21,069 and sprinkling some rust powder on it. 109 00:09:28,279 --> 00:09:31,381 Probably need a little bit more... 110 00:09:34,200 --> 00:09:37,693 You just have to rub it into the sticky side... 111 00:09:41,154 --> 00:09:43,273 Get off all the excess... 112 00:09:43,860 --> 00:09:45,145 Rex: That's it. Tim: Right. 113 00:09:51,138 --> 00:09:56,808 Right, now we record some sig... we put it in an ordinary audio recorder. 114 00:09:56,809 --> 00:10:00,702 Err, yeah I think I've got it in the right place... [clunk] 115 00:10:00,703 --> 00:10:04,085 Rex: Ready. Tim: Play.....yup! [click] 116 00:10:04,086 --> 00:10:09,783 Rex: (loudly and clearly) This is recorded on sticky tape and rust. This is recorded on sticky tape and rust. 117 00:10:10,331 --> 00:10:13,559 Tim: Right! And now all we have to do is play it back again. 118 00:10:13,560 --> 00:10:17,753 Err, that's the right way round... 119 00:10:19,838 --> 00:10:21,834 Put it in... 120 00:10:22,531 --> 00:10:23,890 Right, okay. [clunk] 121 00:10:23,891 --> 00:10:30,809 Rex's voice: This is recorded (quieter) on sticky tape and r..(distorts). This is recorded on sticky tape and... (inaudible) 122 00:10:30,810 --> 00:10:34,131 Tim: Well the start of it was very good. [both giggle] 123 00:10:34,132 --> 00:10:35,720 Rex: Try it again. 124 00:10:35,721 --> 00:10:38,542 Tim: I dunno, why the, why did the quality go down do you think? 125 00:10:38,543 --> 00:10:40,411 Rex: I think it probably fell off the capstan there. 126 00:10:40,412 --> 00:10:42,406 Tim: Well it proves the principle anyway. 127 00:10:42,407 --> 00:10:47,022 Tim: The ring shaped recording head with a gap, that's been used ever since, 128 00:10:47,023 --> 00:10:49,891 was also perfected by the magnetophone company. 129 00:10:49,892 --> 00:10:52,553 Here Rex has made a giant model of one. 130 00:10:52,554 --> 00:10:55,614 If he covers it up and sprinkles on some iron filings, 131 00:10:55,615 --> 00:10:58,882 you can see how the gap concentrates the magnetic field. 132 00:10:58,883 --> 00:11:09,943 [quiet shaking noise] 133 00:11:15,752 --> 00:11:18,655 Now when he pushes a model of the tape past the gap 134 00:11:18,656 --> 00:11:21,493 you can see how it's magnetised. 135 00:11:24,631 --> 00:11:28,201 The smaller the gap, the smaller the magnets created on the tape. 136 00:11:28,202 --> 00:11:30,750 And the more information that can be recorded on it. 137 00:11:30,751 --> 00:11:33,364 That's why video heads are so small. 138 00:11:33,365 --> 00:11:40,094 The gap on the heads on a domestic video machine have to be exactly 3/1000th of a millimetre across. 139 00:11:40,095 --> 00:11:42,828 They're the most accurately made thing in the home. 140 00:11:42,829 --> 00:11:46,462 It's amazing that something so tiny can record anything at all. 141 00:11:46,463 --> 00:11:50,022 But there really is something quite magical about the properties of magnetism. 142 00:11:55,199 --> 00:12:00,095 Rex: Usually my work is making models and special effects for the film, television and advertising industries. 143 00:12:00,096 --> 00:12:02,646 And I use magnetic effects an awful lot. 144 00:12:02,647 --> 00:12:05,126 Simple ones for conjurers and illusionists: 145 00:12:05,127 --> 00:12:10,138 party tricks to get something which is obviously not magnetic like an ordinary match 146 00:12:10,139 --> 00:12:16,716 And you can actually make them dance. 147 00:12:18,534 --> 00:12:21,686 For a simple magnetic trick like this, you need two obvious things. 148 00:12:21,687 --> 00:12:25,777 you need to drill the middle of the match and put an iron pin inside, 149 00:12:25,778 --> 00:12:28,616 and of course you also need Tim underneath the table with a magnet. 150 00:12:28,617 --> 00:12:30,084 You alright under there Tim? 151 00:12:30,085 --> 00:12:33,063 And there's the magnet which we did the trick with. 152 00:12:33,064 --> 00:12:37,045 But of course, sometimes you need much more sophisticated 153 00:12:37,046 --> 00:12:41,056 applications for magnets, and I did one years ago with a friend of mine, 154 00:12:41,057 --> 00:12:43,855 and we had to make a magnetic mint. 155 00:12:43,856 --> 00:12:45,484 You can hear it rattles... [quiet rattling noise] 156 00:12:45,485 --> 00:12:48,402 And er, with a magnet under the table again, 157 00:12:48,403 --> 00:12:50,321 you can control it beautifully. 158 00:12:50,322 --> 00:12:54,015 You can make it go backwards. You can make it turn. 159 00:12:54,016 --> 00:12:55,289 You can swing it round again. 160 00:12:55,290 --> 00:12:57,674 So you've got full control over it 161 00:12:59,958 --> 00:13:02,094 [Duck quacks as if it thinks it's a chicken] 162 00:13:02,095 --> 00:13:05,087 Tim: Magnetic recording of sound is relatively simple. 163 00:13:05,088 --> 00:13:08,300 [duck quacks] 164 00:13:08,301 --> 00:13:10,921 Tim: Recording moving pictures is much more difficult. 165 00:13:10,922 --> 00:13:11,709 [Duck hisses] 166 00:13:11,710 --> 00:13:12,287 Man: Ow! 167 00:13:12,288 --> 00:13:14,686 [Footsteps and wheels squeak] 168 00:13:14,687 --> 00:13:21,083 Tim: In one second, a video recorder has to record 25 complete separate pictures. 169 00:13:21,084 --> 00:13:27,714 Even on a domestic video recorder, each picture is split up into over half a million elements. 170 00:13:27,715 --> 00:13:30,780 And the colour and brightness of each has to be recorded. 171 00:13:30,781 --> 00:13:33,107 [footsteps and rattling] 172 00:13:33,611 --> 00:13:36,111 [scratching of pen on paper] 173 00:13:36,112 --> 00:13:41,864 In one second, an audio recorder only has to record about three words. The average speaking speed. 174 00:13:41,865 --> 00:13:47,877 Hundreds of times more space on the tape is needed to record pictures instead of just sound. 175 00:13:49,892 --> 00:13:53,845 Dimbleby: Good evening, I want you first of all to look at this clock, 176 00:13:53,846 --> 00:13:58,265 And remember the time that it says: just after 9:16. 177 00:13:58,266 --> 00:14:00,026 Now the reason for asking you to do this, 178 00:14:00,027 --> 00:14:04,519 right at the beginning of Panorama tonight, has all to do with VERA. 179 00:14:04,520 --> 00:14:07,127 The Vision Electronic Recording Apparatus. 180 00:14:07,128 --> 00:14:09,403 The new machine which is in programmed service tonight 181 00:14:09,404 --> 00:14:14,041 for the first time at the BBC's research department at Nightingale Square in South London. 182 00:14:14,042 --> 00:14:15,835 There she is. 183 00:14:15,836 --> 00:14:21,222 Tim: Richard Dimbleby demonstrated the BBC's first attempt at video recording in 1956. 184 00:14:21,920 --> 00:14:28,032 To record enough information, VERA had to move the tape past the head at about 20 mph. 185 00:14:28,033 --> 00:14:32,270 The results were shown by replaying the start of the programme. [Dimbleby in background] 186 00:14:32,271 --> 00:14:34,326 Dimbleby: ...to do this right at the beginning of Panorama tonight, 187 00:14:34,327 --> 00:14:39,421 has all to do with VERA. The Vision Electronic Recording Apparatus (fades out) 188 00:14:39,422 --> 00:14:42,987 Tim: It got the nickname of wobbly television, and was very short lived. 189 00:14:42,988 --> 00:14:47,338 Dimbleby: Well, there you are. That's where we came in, in a way. 190 00:14:47,339 --> 00:14:52,292 That was the beginning of Panorama tonight, just about 5 minutes after I first did it. 191 00:14:52,293 --> 00:14:54,539 This is now me again, really. 192 00:14:54,540 --> 00:14:58,722 Tim: Today all video recorders work with slow-moving tape. 193 00:14:58,723 --> 00:15:04,357 to make enough space, the heads have to record a series of diagonal stripes across the tape. 194 00:15:04,358 --> 00:15:09,511 These stripes are created by spinning the heads round on a drum while the tape moves slowly past. 195 00:15:10,299 --> 00:15:16,089 Here we've replaced the heads with pens and and if I thread up a bit of paper 196 00:15:16,090 --> 00:15:18,790 with Rex - yeah I think that's in alright now. 197 00:15:18,791 --> 00:15:23,575 Okay, you should now be able to see a stripe being created. 198 00:15:23,576 --> 00:15:27,005 It's the tilt of the drum which makes the stripe be diagonal. 199 00:15:27,006 --> 00:15:29,803 And by the time that one stripe's reached the top. 200 00:15:29,804 --> 00:15:34,650 The tape will have moved on, just far enough so that the next stripe doesn't overlap. 201 00:15:34,651 --> 00:15:40,452 [quiet drum and clicking noises] 202 00:15:49,207 --> 00:15:52,754 But of course in a real machine the stripes are much closer together. 203 00:15:55,929 --> 00:15:58,286 Tim: This machine's all still connected up. 204 00:15:58,287 --> 00:16:02,084 And if Rex and I lace up a bit of tape. 205 00:16:02,085 --> 00:16:03,941 Bit tricky to get it right... okay... 206 00:16:03,942 --> 00:16:09,637 [quiet motor noises] 207 00:16:09,638 --> 00:16:12,575 You can see that when the tape's stationary. 208 00:16:12,576 --> 00:16:16,219 The heads are, the spinning heads are reading one stripe over 209 00:16:16,220 --> 00:16:19,059 and over again and this produces the still picture. 210 00:16:19,060 --> 00:16:24,682 Moving the tape backwards and forwards... we're not on a moving bit at the moment... 211 00:16:24,683 --> 00:16:29,382 Er, here. Moving the tape backwards and forwards changes the picture. 212 00:16:29,383 --> 00:16:33,182 It's not a very good picture because my fingers are creating quite a lot of interference. 213 00:16:33,971 --> 00:16:37,761 And of course if you move it at 25 stripes a second. 214 00:16:37,762 --> 00:16:40,703 it replays the tape exactly as it was recorded. 215 00:16:40,704 --> 00:16:44,229 ...whoops... [clicks and rattles] 216 00:16:44,230 --> 00:16:49,229 Spinning the heads is a much more practical way of recording pictures than speeding up the tape. 217 00:16:50,284 --> 00:16:54,200 The idea comes from this German military machine the Tonschreiber. 218 00:16:54,201 --> 00:16:59,622 Based on the magnetophone of the 1930s, er, this machine was used 219 00:16:59,623 --> 00:17:04,468 throughout the second world war for broadcasting propaganda speeches and marshal music. 220 00:17:04,469 --> 00:17:07,647 Its sound quality was much better than anything the Allies had. 221 00:17:07,648 --> 00:17:11,765 It's a bit difficult to get it to run at the right speed. Erm... 222 00:17:12,706 --> 00:17:17,512 [German music starts slowly, then speeds up and runs too fast] 223 00:17:17,513 --> 00:17:40,251 [Music settles to correct speed and plays] 224 00:17:42,265 --> 00:17:45,283 After the war, many of these machines were captured. 225 00:17:45,284 --> 00:17:50,305 And two found their way to a Russian engineer living in California called A. M. Poniatov. 226 00:17:50,306 --> 00:17:55,157 He ran a small firm producing electric curling tongs, called Ampex. 227 00:17:55,158 --> 00:17:58,602 AMP after his initials, plus EX for excellence. 228 00:17:59,664 --> 00:18:02,903 Poniatov wanted to develop the machine, but lacked the capital. 229 00:18:04,026 --> 00:18:07,580 Fortunately he found an enthusiastic investor keen to develop 230 00:18:07,581 --> 00:18:11,764 new ways to immortalise his stage performances. Bing Crosbie. 231 00:18:11,765 --> 00:18:16,547 With Bing's money, Ampex audio recorders soon became the industry standard. 232 00:18:19,281 --> 00:18:23,189 Unlike other companies, Ampex started its work on video by 233 00:18:23,190 --> 00:18:25,546 experimenting with spinning heads. 234 00:18:25,547 --> 00:18:28,362 There were formidable electronic problems to be overcome 235 00:18:28,363 --> 00:18:31,042 to squeeze the video signal onto the tape. 236 00:18:31,043 --> 00:18:34,967 But by 1956 they had perfected a broadcast quality machine. 237 00:18:40,992 --> 00:18:44,503 This is their earliest surviving recording... [silent] 238 00:18:50,905 --> 00:18:57,396 This is one of their first colour recordings, unfortunately the sound has been lost. 239 00:18:59,925 --> 00:19:03,793 [High pitched tape motors] The quality of the pictures on these Ampex machines became very good. 240 00:19:03,794 --> 00:19:09,122 This machine in the BBC video library was built in the late 60s. 241 00:19:09,123 --> 00:19:15,217 Ampex had updated the styling but it still worked in basically the same way. [motor noise] 242 00:19:15,218 --> 00:19:19,356 However, the heads gradually wear the oxide off the tapes. 243 00:19:19,357 --> 00:19:21,559 They can only be played about thirty times, 244 00:19:21,560 --> 00:19:24,494 and the loose oxide has to be regularly swept up. 245 00:19:26,735 --> 00:19:29,816 This is the next generation of Ampex machine 246 00:19:29,817 --> 00:19:33,997 The tape is half the width, and the machine doesn't wear the oxide off. 247 00:19:33,998 --> 00:19:38,568 These machines provided a basis for the first domestic video recorders. 248 00:19:38,569 --> 00:19:42,344 And have also remained a broadcast standard ever since. 249 00:19:43,667 --> 00:19:46,922 Machines like this could be made much much smaller. 250 00:19:46,923 --> 00:19:49,927 But by 1970 the audio cassette had become established 251 00:19:49,928 --> 00:19:52,415 and it was obvious that a cassette video system would 252 00:19:52,416 --> 00:19:54,242 be more suitable for a domestic machine. 253 00:19:54,243 --> 00:19:56,996 Particularly because it would protect the fragile heads. 254 00:19:56,997 --> 00:19:59,826 Philips introduced the first machine like this. 255 00:19:59,827 --> 00:20:04,360 The N1500 in 1972. This one's actually a bit later. 256 00:20:04,361 --> 00:20:08,281 But it uses the same square cassettes with one reel on top of the other. 257 00:20:08,282 --> 00:20:10,979 [clank rattle clank] 258 00:20:10,980 --> 00:20:14,540 This was followed by the, another Philips system the V2000. 259 00:20:14,541 --> 00:20:16,254 The Sony Betamax. 260 00:20:16,255 --> 00:20:17,698 The Sony Video Eight. 261 00:20:17,699 --> 00:20:19,816 And of course, VHS. 262 00:20:19,817 --> 00:20:24,433 [Whirr and click of tape-load mechanism] 263 00:20:24,434 --> 00:20:28,552 The cassette system does add greatly to the mechanical complexity of the machine. 264 00:20:28,553 --> 00:20:31,537 Bringing the cassette in and wrapping it around the drum 265 00:20:31,538 --> 00:20:34,399 needs two completely separate mechanisms. 266 00:20:34,400 --> 00:20:36,913 [VCR whirring] 267 00:20:36,914 --> 00:20:42,595 It's all wonderfully ingenious, but it does look a bit out of place in this age of solid state technology. 268 00:20:42,596 --> 00:20:48,620 [motor noise] [whirr-clack-whirrr] 269 00:20:48,621 --> 00:20:52,612 The electronics are just as ingenious, although it's not quite so obvious. 270 00:20:52,613 --> 00:20:55,810 A domestic machine only records half as much information about 271 00:20:55,811 --> 00:20:58,201 each picture as a broadcast quality one, 272 00:20:58,202 --> 00:21:00,544 but the difference is hardly noticeable. 273 00:21:00,545 --> 00:21:03,360 It is only when you record from one tape to another a few times, 274 00:21:03,361 --> 00:21:07,509 that the electronics have problems and the imperfections start to show up. 275 00:21:07,510 --> 00:21:11,529 This is an original recording. 276 00:21:11,530 --> 00:21:15,747 [Derrr... derr... der-derr... - 80s Channel 4 music] 277 00:21:15,756 --> 00:21:18,123 The quality's really very good. 278 00:21:18,124 --> 00:21:21,700 But unlike broadcast machines, the quality of the second 279 00:21:21,701 --> 00:21:24,838 and subsequent generations quickly deteriorates. 280 00:21:24,839 --> 00:21:29,455 [music becomes more crackly] 281 00:21:29,456 --> 00:21:32,613 First the picture gets less sharp. 282 00:21:32,614 --> 00:21:35,097 [sound increases in crackliness and tinniness] 283 00:21:35,098 --> 00:21:39,477 Then the colour stops fitting the picture and the vertical lines get more ragged. 284 00:21:40,037 --> 00:21:42,528 [very crackly, some whistle] 285 00:21:42,529 --> 00:21:47,612 Then the sound deteriorates and the colour, which is recorded separately, disappears. 286 00:21:47,613 --> 00:21:49,312 [sound cutting out] 287 00:21:49,313 --> 00:21:53,189 Finally the picture and the sound break up completely. 288 00:21:53,190 --> 00:22:03,295 [infrequent bursts of sound] 289 00:22:04,536 --> 00:22:07,152 Video recorders have now been around for over 10 years. 290 00:22:07,153 --> 00:22:10,294 And in that time their design has changed quite considerably. 291 00:22:10,295 --> 00:22:12,723 Some things have definitely improved. 292 00:22:12,724 --> 00:22:16,791 The early machines used to have lots of belt drives, basically rubber bands. 293 00:22:18,316 --> 00:22:20,801 And these things used to stretch and perish. 294 00:22:20,802 --> 00:22:23,716 Rex and I had this problem with these beavers. 295 00:22:23,717 --> 00:22:26,883 We made 12 for a publisher to go in shop windows. 296 00:22:26,884 --> 00:22:30,510 And they had belt driven motors in the base. 297 00:22:30,511 --> 00:22:35,298 None of them worked for more than a week, and I've been very wary of belt drives ever since. 298 00:22:37,378 --> 00:22:41,050 Today the rubber bands in video recorders have been replaced by 299 00:22:41,051 --> 00:22:43,858 gears and other mechanisms that are much more reliable. 300 00:22:43,859 --> 00:22:47,645 [click click click] 301 00:22:47,646 --> 00:22:50,982 The old machines were twice the size and weight of the new ones. 302 00:22:52,708 --> 00:22:57,351 Without modern microprocessor chips, the old machines had three times as many components. 303 00:23:00,211 --> 00:23:04,587 This miniaturisation does have some drawbacks though when it comes to repairs. 304 00:23:04,588 --> 00:23:10,430 Rex: These little black dots on here, are actually this component in miniature. 305 00:23:10,431 --> 00:23:17,462 and it's bad enough replacing one of these tiny things, without trying to replace one of these little tiny, er, modern resistors. 306 00:23:17,463 --> 00:23:20,095 You need a remarkable eyesight to be able to do it. 307 00:23:20,850 --> 00:23:24,610 And of course problems we do have, as children see mummy and daddy 308 00:23:24,611 --> 00:23:28,212 pushing videos in here, so they have a nasty habit of putting things there as well, 309 00:23:28,213 --> 00:23:32,843 they can be anything from sticky jam sandwiches and toast to toys and all sorts of things. 310 00:23:32,844 --> 00:23:36,054 And of course that doesn't do the tape transport mechanism any good either. 311 00:23:37,397 --> 00:23:39,432 Dad: Okay, so I just put it on Yah? 312 00:23:39,433 --> 00:23:45,866 Tim: The other problem with video recorders, is that they're not getting any easier to use. 313 00:23:45,867 --> 00:23:49,398 Dad: What am I doing wrong Melia? Melia: Is there a green liiight? 314 00:23:49,399 --> 00:23:53,370 Dad: No. Melia: Is it 22:00 hours or eight? 315 00:23:53,371 --> 00:23:57,726 Dad: Well how can I see. Melia: I say.. I think it's page 43... 316 00:23:57,727 --> 00:24:02,096 Dad: Maybe we need the thingy? Melia: Oh, the thingy? 317 00:24:02,097 --> 00:24:07,888 Melia: Oh, you mean the remote thingy? Dad: Yah! 318 00:24:07,889 --> 00:24:11,468 Dad: Just numbers, you know, it means nothing. 319 00:24:13,586 --> 00:24:20,359 Dad: Ohh! Well, it's all wired in at the back! Melia: Not there... Not there... 320 00:24:20,360 --> 00:24:24,911 [MEROWWW!] Melia: Oh, here it is! 321 00:24:24,912 --> 00:24:27,713 Dad: Great, oh but it's not going! 322 00:24:27,714 --> 00:24:33,059 Dad: Hi Cressida... Cressida: Let me do it dad, it's really easy. 323 00:24:33,160 --> 00:24:36,121 [Channel 4 music] Dad: Oh. Great. 324 00:24:36,122 --> 00:24:40,420 Tim: Well video recorders may not be perfect, but I still think it's a miracle that they work at all. 325 00:24:40,421 --> 00:24:45,119 The illusion of reality they create is so convincing it's very hard to believe 326 00:24:45,120 --> 00:24:48,809 that what you've been watching for the last half an hour is really just a load of rust. 327 00:24:48,810 --> 00:25:44,278 [Jazzy music: 'Take 5' - Dave Brubeck]