1.8.1 FM Stereo History

A brief history • 1931 – Alan Blumlein, working for EMI in London patents the stereo recording technique, using a figure-eight miking arrangement. • 1933 – Armstrong demonstrates FM transmission to RCA • 1935 – Armstrong begins 50kW experimental FM station at Alpine, NJ • 1939 – GE inaugurates FM broadcasting in Schenectady, NY – TV demonstrations held at World’s Fair in New York and Golden Gate Interna- tional Exhibition in San Francisco – Roosevelt becomes first U.S. president to give a speech on television – DuMont company begins producing television sets for consumers • 1942 – Digital computer conceived • 1945 – FM broadcast band moved to 88-108MHz • 1947 – First taped US radio network program airs, featuring Bing Crosby – 3M introduces Scotch 100 audio tape – Transistor effect demonstrated at Bell Labs • 1950 – Stereo tape recorder, Magnecord 1250, introduced • 1953 – Wireless microphone demonstrated – AM transmitter remote control authorized by FCC – 405-line color system developed by CBS with ”crispening circuits” to improve apparent picture resolution 1 – FCC reverses its decision to approve the CBS color system, deciding instead to authorize use of the color-compatible system developed by NTSC – Color TV broadcasting begins • 1955 – Computer hard disk introduced • 1957 – Laser developed • 1959 – National Stereophonic Radio Committee formed to decide on an FM stereo system • 1960 – Stereo FM tests conducted over KDKA-FM Pittsburgh • 1961 – Great Rose Bowl Hoax University of Washington vs. Minnesota (17-7) – Chevrolet Impala ‘Super Sport’ Convertible with 409 cubic inch V8 built – FM stereo transmission system approved by FCC – First live televised presidential news conference (John Kennedy) • 1962 – Philips introduces audio cassette tape player – The Beatles release their first UK single Love Me Do/P.S. I Love You, on EMI/Parlophone Records • 1969 – Neil Armstrong walks on the moon (July 21); worldwide audience watches the event live FM Stereo Format 1 We have seen how frequency modulation can be used to encode a signal. But for stereo you need two signals. How can you put two signals on an electromagnetic wave? The answer is that you actually combine more than one wave. The FM broadcast for a stereo signal from a commercial radio station is actually fairly complicated. It contains a frequency modulated carrier wave that is modulated with the left plus right channel audio signals. In addition, 1from Dr. Malcolm Ingham, Victoria University of Wellington, New Zealand. 2 Figure 1: FM stereo spectrum there is plus an amplitude modulated “sub-carrier” at 38 KHz higher frequency than the FM modulated carrier. The AM modulated carrier is modulated with left-right signal. An older mono receiver would play only the left + right signal. The stereo receiver would get the L+R and L R signals and use them to produce L and R separately. These were then sent to the two speakers. Finally, another signal is added at 19 KHz above the FM modulated carrier. This signal, called a pilot signal, makes the receiver aware that this is a stereo broadcast. The EM wave from and FM stereo station is complicated to look at in time domain, but in frequency domain it is easier to understand. Figure 1 shows a sketch of the FM radiostation EM wave versus frequency. 3 The Great Rose Bowl Hoax 04/13/2006 05:07 PM The Great Rose Bowl Hoax January 2, 1961: a capacity crowd filled the Rose Bowl > > Click here for 2006 Rose Bowl Tickets! < < stadium to watch the Minnesota Golden Gophers take on the Washington Huskies in the New Year's Day game (played that year on January 2 because the 1st fell on a Sunday). Millions more watched around the nation, crowded in front of tv sets in living rooms, restaurants, and bars. NBC was providing live coverage of the game. At the end of the first half the Huskies led 17 to 0, and everyone settled in to watch the half-time show for which the Washington marching band had prepared an elaborate flip- card routine. Sets of variously colored flip cards and an instruction sheet had been left on seats in the section of the stadium where the Washington students were located. When the students heard the signal from the cheerleaders, they were each supposed to hold up the appropriate flip card (as designated by the instruction sheet) over their head. In this way different gigantic images would be formed that would be visible to the rest of the stadium, as well as to those viewing at home. The Washington band planned on displaying a series of fifteen flip-card images in total. The flip-card show got off to a well-coordinated start. Everything went smoothly, and the crowd marvelled at the colorful images forming, as if by magic, at the command of the cheerleaders. It wasn't until the 12th image that things began to go a little wrong. This image was supposed to depict a husky, Washington's mascot. But instead a creature appeared that had buck teeth and round ears. It looked almost like a beaver. The next image was even worse. The word 'HUSKIES' was supposed to unfurl from left to right. But for some reason the word was reversed, so that it now read 'SEIKSUH'. These strange glitches rattled the Washington cheerleaders. They wondered if they might have made some careless mistakes when designing the complex stunt. But there was nothing for them to do about it now except continue on, and so they gave the signal for the next image. What happened next has lived on in popular memory long after the rest of the 1961 Rose Bowl has been forgotten. It was one of those classic moments when a prank comes together instantly, perfectly, and dramatically. The word 'CALTECH' appeared, held aloft by hundreds of Washington students. The name towered above the field in bold, black letters and was broadcast out to millions of viewers nationwide. > > Click here for 2006 Rose Bowl Tickets! < < For a few seconds the stadium was plunged into a baffled silence. Everyone knew what Caltech was. It was that little Pasadena technical college down the road from the Rose Bowl stadium. What no one could figure out was what its name was doing in the middle of Washington's flip-card show. Throughout the United States, a million minds simultaneously struggled to comprehend this enigma. In fact, only a handful of people watching the game understood the full significance of what had just happened, and these were the Caltech students who had labored for the past month to secretly alter Washington's flip-card show. The idea for the prank had arisen out of the indignation that a group of Caltech students (who would come to be known as the "Fiendish Fourteen") felt at Caltech's lack of representation at the Rose Bowl's famous New Year's Day game. After all, the Rose Bowl stadium was right in Caltech's backyard, and the Caltech team often played there. But every year the technical college, despite its many merits, was entirely ignored in the hype building up to the game. This group of students decided to rectify the situation. They determined to make sure that Caltech got some recognition at the upcoming game, and Washington's flip-card show seemed to be the perfect vehicle for achieving their goal. Pulling off the prank required obtaining a detailed knowledge of how Washington's flip-card system worked. http://www.museumofhoaxes.com/pranks/rosebowl.html Page 1 of 3 The Great Rose Bowl Hoax 04/13/2006 05:07 PM This knowledge was acquired simply by asking Washington's head cheerleader to explain it to them. Of course, the cheerleader was under the impression that he was explaining the system to a curious reporter from a local Los Angeles high school. What he didn't know was that the reporter was actually a Caltech student in disguise. What the Fiendish Fourteen discovered was that to alter the show it would simply be necessary to change what was written on the instruction sheets that would be left on the seats—all 2,232 of them—blocked off for the Washington fans. This was a daunting task, but the Fiendish Fourteen were up to it. They staked out the hotel where the Washington cheerleaders were staying. When the cheerleaders were away they broke into their rooms and removed a single instruction sheet. This they took to a printer and had him print up 2,232 exact duplicates. A moment of panic occurred when it was realized that the new sheets looked conspicuously less worn than the old ones. But it was decided that since the sheets would be replaced en masse, this lack of aging might not be noticed. Then each sheet had to be individually marked up by hand according to Caltech's new master plan, so that the seat numbers and card designations would be correct. This was done all in one marathon session on New Year's Eve at Lloyd House, the home of the Fiendish Fourteen. When the task was done, three students were dispatched back to the hotel of the Washington cheerleaders to switch the old sheets with the new, altered ones. The cheerleaders, as was known beforehand, were away from their rooms visiting Disneyland. The switch completed successfully, the Fiendish Fourteen sat back and nervously waited for their scheme to come to fruition. Luck was on their side, and all the elements of the plan came together better than they had imagined possible. The first eleven images of the flip-card show had been left basically unaltered, to allay suspicion. The first real alteration occurred with the 12th image, which had been changed from a husky to a beaver, Caltech's mascot.

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