ON THE RADIO
Mike "Crusty" Johnson
I’ve been studying electronics since I was 15 years old. And I’m still learning. When I started in electronics, TV sets were manufactured using exclusively vacuum tubes and discrete components. The typical radio was manufactured with vacuum tubes, as were the so called home entertainment systems with phonograph and/or reel-to-reel tape machines. Hi-fi audio was introduced, when I was in junior high school, and stereo audio was introduced before I graduated high school. NTSC color TV was introduced, in 1954, but there was no color TV in my parent’s home, until 1963.
I remember that AM/FM stereo radio was tried out in the ‘40s and ‘50s. I really remember it from the Fifties, as I was too young, in the forties. I mean this was AM-FM stereo, with the left channel on one frequency and the right on another frequency of a different modulation scheme. The FCC actually approved this system, no matter that it was extremely difficult and expensive to implement. AM/FM stereo radios were made and sold, in the 40s and 50s, although transmitter systems were few and far between. You needed a FM transmitter and an AM transmitter. On the receive end you needed two receivers, one AM and one FM, connected to separate speakers, or a receiver that had two separate tuners, one AM and one FM, which could be tuned separately, and in which one fed the left speaker and the other fed the right speaker.
According to historians, AM radio and FM radio should have grown concurrently, but, because RCA was heavily vested in AM radio, they actually influenced the FCC to make changes to the frequency spectrum that effectively put FM behind AM for several decades. This was a prime example of those with money and power (RCA) taking advantage of those with lesser wealth and power (Edwin Armstrong, the father, so to speak, of FM radio).
I remember that FM stereo radio was made available and approved by the FCC, in the sixties, but, stereo for AM radio, although the technology was available, was denied approval. This was done in order to allow FM radio to catch up with the popularity of AM radio. Ironically, by the end of the Seventies, FM radio was ahead of AM radio in popularity. So much so, that the FCC did approve AM stereo radio in the eighties.
An anecdote from my past: My first personal experience with full Hi-Fi stereo audio was late 1962 or early 1963, what’s a few months, here or there? I had been sleeping for about an hour after working a 12 hour night shift. I was awakened by the sound of a jet aircraft buzzing our barracks. As I became more cognizant of my surroundings, I realized that the sound appeared to be coming from inside our building and this jet was flying from one end of the building to the other. I jumped from the bed, ran to the door and opened it. There was nothing in the hallway, that could be seen! After looking up and down the hallway, I eventually noticed two large speaker enclosures, one at each end of the hallway. At about the same time, it started again. It was the sound of a jet plane flying down the hallway, passing right in front of me. To the uninitiated, it seemed real. In reality, it was the opening sequence of an album named: “The songs of the Fighting Air Force” being played on a Stereo Hi-Fi turntable through a 100 watt per channel stereo amplifier that belonged to one of the airmen living on our floor. He just wanted to see how well it really worked, which was very. The aircraft was an F-86 Saber Jet.
Eniac was the first electronic digital computer system and was conceptually developed over a period beginning in 1939 and ending in 1946. It was developed for the US Army by the Moore School of Electrical Engineering of the University of Pennsylvania. The concept was developed over the period of 1939 through 1942 and initial construction was completed in 1946, with what they called final assembly taking place during the fall of 1945.
The original purpose, for the computer, was to provide a reliable means of developing ballistics and bombing trajectory tables. However, during its tenure, which ended in 1955, Eniac was used for a myriad of scientific calculations. When put on line, in 1946, Eniac weighed over 30 tons, utilized over 1,000 square feet of space. It was made up of 19,000 vacuum tubes, 1500 relays and hundreds of thousands of resistors, capacitors and inductors which consumed over 200 kilowatts of power.
During its construction, many concepts were developed such as multi-vibrators (Flip-Flops), “and” and “or” gates, data buffers and most other “logic” used in later computers. Initially, program and address inputs were parallel, but in later years, in order to speed up programming, were changed to serial inputs. Also, a whopping 100 words of magnetic core memory was added, before its demise. 100 words is equivalent to about 100 bytes of data.
Among other things, the term “debugging” came into existence, during the development of Eniac. As the story goes, after the final assembly, in 1945, after the computer was installed at the Ordinance Ballistic Research Laboratories, the computer failed some operations it had previously passed. In tracing the problem to its source, the engineers found a moth between a pair of contacts in the relay tree. As long as relays were used, in computers, insects did occasionally cause problems. Ergo the term “debugging” evolved from working the bugs out of the system.