Miniaturised Radios and Magnetic Tape

CES and the Downsizing of Consumer Electronics

Reprinted from Paleotronic issue 1, volume 1 Feb-Mar 2018. 

Lee De Forest’s 1907 Audion vacuum tube is widely credited with kickstarting the modern electronics industry in general, but it would take the much smaller, lower-power and cooler transistor to shift it into high gear.

The thermonic triode, a vacuum tube similar to the one pictured, works by using heat to modify the conductive properties of a fillament. In 1880, Thomas Edison discovered that, when a parallel current was applied to the lament circuit, the charge in the hot lament could be amplified, or cut off. Edison used his “thermonic diode” to power the first telegraph stations. The triode added a charged grid that could modify the current.

German physicist Julius Edgar Lilienfeld filed patents in the US and Canada for a field-effect transistor during the 1920s, which was intended to be a solid-state re- placement for the power-hungry, fragile thermonic triode vacuum tube (see sidebar). It was (and is) able to both act as an electronic logic gate (used in modern computer circuitry) using a two-terminal electron “channel” (with a “source” and a “drain”, and a one-terminal “gate”), and as an amplifier, able to build up the strength of a signal by using current to narrow the channel at one end; however, the materials necessary to make his invention practical would not exist for another twenty years.

In 1947 John Bardeen and Walter Brattain, scientists at AT&T’s Bell Labs in Murray Hill, New Jersey who were researching the conductive properties of materials, observed that when two gold terminals were applied to a crystal of germanium (a semiconductor – that is, an element whose qualities of conductivity – or ability to carry electric current – can be modified by adding impurities to, for example, increase resistance in a particular direction), an output signal was produced with greater power than the input –an amplifier.

Solid State Physics Group leader William Shockley saw the potential in this, and over the next few months worked to greatly expand the knowledge of semiconductors. Shockley initially wanted to patent a field-effect transistor, but having unearthed Lilienfeld’s patents, Bell Labs’ lawyers advised against it. Instead, what Bardeen, Brattain and Shockley invented in 1947 was the first “point-contact transistor”– for which they would win the Nobel Prize.

The device consisted of two terminals (an “emitter” and a “col- lector”) mounted on a triangle of plastic, each contacting a layer of germanium, itself layered on a base of metal. When a small current was applied to the emitter, the current flowing from the emitter to the base was increased by a greater amount, thus acting as an amplifier. It was soon superseded by an improved version, called a bipolar junction transistor, which, in part, reversed the flow from the base to the collector, and is how transistors function today. Germanium has also since been replaced by silicon and other alloys.

Over time, the transistor became smaller and smaller – there are billions in a modern computer microprocessor!

Tiny CRTs

The cathode-ray tube (or CRT) used in older televisions is a vacuum tube that contains one or more electron guns and a phosphorescent screen that converts these streams of electrons into light. In television sets, an electromagnetic field is used to bend the electron streams, forcing them to scan across the screen in horizontal lines in a vertical pattern called a “raster”.

At CES in 1969 Panasonic introduced a 1.5 inch (38mm) CRT. “What could such a tiny thing be good for?” you may ask. Well, initially used in oscilloscopes, it would eventually be used in Sony’s “Watchman” portable television sets in the early 1980s, and as view finders in video cameras up until the early 21st century.

Although they may seem primitive in to- day’s world of LCD and LED displays, the abilities granted by these tiny CRTs – to produce smaller electronics diagnostic equipment, watch television anywhere, and to record video confident in the look of the final product – contributed to an ongoing trend toward miniaturisation that led us to live in the mobile world we have today.

The Cassette Comes to Video

The audio cassette, developed by electronics manufacturer Philips in Belgium and released in 1963, was originally developed for use in dictation machines. As fidelity improved, it would eventually replace 8-track tapes (see Pop Culture) in the late 1970s, but Sony wondered if there was another potential use for the cassette format in the videotape market. However, unlike an audio cassette, the reels in Sony’s implementation turn opposite directions to each other. This is to ensure the videotape remains tight during playback, to avoid glitching. “U-Matic” (as Sony called their format) also featured a rudimentary form of write protection, by means of a sticker affixed over a hole in the bottom of the videocassette.

It was originally Sony’s intention to market U-Matic recorders towards the consumer to record and store live television broadcasts, but the high cost of the machines and the cassettes made the retail price extremely unattractive to casual users. However, U-Matic was popular amongst businesses (which used it to communicate between business units and to clients and customers,) and educational companies, who produced videocassettes for use by schools.

U-Matic also found popularity in the broadcast sector, which had struggled previously to deliver up-to-date news broadcasts using 16mm film, which required time to develop. After Sony’s introduction of a portable U-Matic recorder in 1974, the news industry quickly took up the format, which allowed them to record and broadcast footage as quickly as they could get it back to the studio. This ushered in the modern era of Electronic News Gathering (or ENG).

The introduction of a “higher band- width” U-Matic format in the early 1980s was the final nail in the coffin of the use of 16mm film for news. Its improved colour quality and reduced noise removed any advantage that remained in film. Further, the eventual introduction of remote microwave and satellite transmitters further increased the potential immediacy of news coverage to instant, something impossible with film.

While U-Matic would eventually be replaced by Sony Betacam, it became a standard in professional video for many years, and was an important precursor to subsequent videotape formats such as Betamax and VHS, the price of which, unlike U-Matic, would eventually come down and finally popularise the ownership and use of home videocassette recorders in the 1980s.

How does videotape work?

Unlike audio cassettes, which store a single signal recorded and played back using one stationary magnetic “head”, analogue videotape uses a moving cylindrical “drum” which records signals using a method called “helical scan”.

Audio tape moves at a constant speed and provides limited “bandwidth”, or frequency resolution. To record video, such a system would need an immense amount of tape moving at high speed, which is impractical. Instead, helical scan rotates a drum contain- ing one or more heads while the tape moves over it at an angle. This causes the signal to be imprinted using diagonal stripes, and uses much less overall length of tape than linear methods.

You’re cruising along in your brand-new 1968 Ford Fairlaine, and you want to listen to some tunes. What can you do?

Well, listening to vinyl was largely out. While some in-car record players did exist, they weren’t very practical while you were moving! The quality of cassette was not good yet, and reel-to-reel tape was too bulky and cumbersome for the car. FM radio wasn’t common yet either!

Luckily, you have 8-track. Initially developed for use in radio stations, the single-reel, four-track Fidelipac cartridge format was later refined for use in automobiles, adding two additional programs each using two tracks, for a total of eight, which allowed for around 80 minutes of playback. Plenty of time to cruise around before you have to change the tape! The playback head would automatically shift to the next two tracks at the end of each “program” too, and because the tape looped back on itself, you could just listen to the same cartridge over and over, if you wanted to. Problem solved!

Thing is, you couldn’t fast-forward or rewind. Or skip to your favourite song. It was like your own personal radio station, in both good ways and bad. Also, the player would sometimes “eat” the tape! The play head could misalign and you’d hear a cacophony of two songs at the same time! Augh! Despite these shortcomings, 8-track would survive until the late 1970s, when the quality of cassettes improved enough to replace them. However, 8-track had one more trick left up its sleeve that cassette could never match.

At the 1971 CES, Quadraphonic 8-track was introduced. Instead of four programs there were two, but they each had four channels of sound (two to the front and two to the rear). Most “quadraphonic” cartridges added little value to the experience, but Isao Tomita’s 1976 “Firebird” was a notable exception. The electronic music pioneer’s rendition of Igor Stravinsky’s “The Firebird” is particularly groovy, and at its purest on 8-track – vinyl quad “encoded” the extra channels: less groovy.

Mamma mia!

At 1993’s CES, Nintendo premiered the trailer for their upcoming Super Mario Bros. movie, in which two Brooklyn plumbers are swept into another dimension where they must do battle with villains from the video game, rescue the Princess, and prevent King Koopa from taking over our world. Sound good?

Problem: The movie really sucked!

The studio Nintendo sold the rights to took serious liberalities with the storyline. Instead of the Mushroom Kingdom, there was now Koopa City (complete with cars) in the middle of a desert. The husband-and-wife directing team was reportedly incompetent. The actors took up drinking!

Dennis Hopper (who played Koopa) joked: “My six- year-old son at the time – he’s now 18 – he said, ‘Dad, I think you’re probably a pretty good actor, but why did you play that terrible guy King Koopa in Super Mario Bros.?’ and I said, ‘Well Henry, I did that so you could have shoes,’ and he said, ‘Dad, I don’t need shoes that badly.’” Enough said.

Sony’s Walkman debuted in 1979, but 1981’s CES saw its monopoly over portable cassette players come to an end.

Sony co-founder Masaru Ibuka liked to listen to opera on long flights, but found existing stereo portable cassette solutions too cumbersome. He wanted something lightweight with good battery life, and directed his company to develop a new product. They succeeded, and dubbed it the “Walkman”.

Despite its high price ($150 1981 dollars – close to $500 today) the Walkman sold well, but it was inevitable that competitors were going to “knock it off”. Rival manufacturers Sanyo and Craig would introduce their own versions, but with a lower price ($99 MSRP, but often sold for less) and others would soon follow.

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