Tuesday, August 10, 2010

Radio Daze

My father liked to tell the story about his father-in-law, Jacob Czerniak, who came to our house to help him install an antenna for our new American Bosch radio. This was in the 1930’s. In those early days of radio, a long antenna was necessary for good reception because the signals were weak. The antenna wire was strung from the radio in the dining room, out the window, up the outside wall and then out to a mast at the end of our house. From there, the wire was strung across the back yard to another mast mounted on the garage roof. Whereupon my grandfather asked: Where does it go from here? He could not understand that the antenna wire simply ended in mid air.
(My grandfather’s puzzlement is not unlike a question I have in trying to understand how people can be walking about with a cell phone to their ear and the signal “knows” where they are; they could be in Seattle or Philadelphia. Another puzzle is seeing multiple people in a relatively small area on separate calls. Are we being irradiated with telephone signals all the time, wherever we are?)
The American Bosch radio was like a piece of furniture, an elegant cabinet standing on its own legs. I was fascinated by the complexity of the “innards” of the radio, as they could easily be seen from the back by sliding out the chassis to see all the glowing vacuum tubes and other electronic parts. The tube filaments were easily visible because the radio tubes were the size of a cucumber. As best I can recall, that radio looked something like this:








This is the radio that the family used to listen to President Roosevelt’s fireside chats. Despite its age, its sound remained good for an AM radio, and the family kept this radio as long as I can remember, at least up until the time I left home for graduate school in 1954.

My own direct involvement with radio began with building a crystal set radio. Before radios were developed that had built-in amplifiers and speaker systems as in our Bosch radio, some adventuresome people had crystal set radios. A crystal set radio is a “passive” radio in the sense that there is no amplification of the signal. For this reason, ear phones are necessary to hear whatever signal is picked up by the antenna. A mineral called galena (lead sulfide), a forerunner of today’s semiconductors, has the property of responding to the faint currents brought in by the antenna. When a “sensitive” spot on the surface of the crystal is touched by a conductive probe, the signal is strong enough to be heard on the ear phones. The probe consists of a straight, stiff wire, mounted on a pivot so that the wire tip can be moved about the surface of the crystal to find a sensitive spot. Hence, crystal set radios were often referred to a “cat whisker’s receivers.”

All that is needed to create a crystal set radio (other than the crystal) are ear phones, an antenna and a winding of copper wire around a cylinder such as a discarded toilet paper core. For those so inclined, this is a sketch of the radio.



My next venture into radio construction did not occur until I was in graduate school, and my room mates and I decided that we needed an FM radio in our dining room where we spent most of our time together. I managed to make a very simple radio from some parts I found in the lab from a circuit design sketched out by one of the instrument makers in the chemistry department.

By the time Bette and I were married in 1959, long playing records, turning at 33 1/3 rpm, had become well established, and with the “extended play” feature, a single disc was capable of holding a complete symphony, albeit on two sides. This was a boom to the classical music recording industry. LP’s soon totally replaced the 78 and 45 rpm records for all types of music. Further, the fidelity of the recordings had increased so that the old record players built to the standards of the 78 rpm records where considered inadequate. However, high quality record turn tables and amplification systems had not yet been marketed at reasonable prices. Consequently, shortly after our marriage, we bought a Heath high fidelity “hifi” kit (Heathkit Mark IV). It took a couple of weeks to assemble a preamplifier and amplifier on a card table in the living room of our rented apartment. Tucked away in our hi-fi cabinet we still have about 166 of those old LP records waiting to be converted to the latest technology.

But the thirst for better and better fidelity was launched. Our next venture in this direction was the purchase of an Ampex reel-to-reel recorder/player. The reels were 7 inches in diameter and had 4 tracks playing at 7 ½ inches per second. Again a complete symphony can be captured on a reel. But in the era of the late 1970’s and 1980’s technology was developing very fast, and the reel-to-reel technology did not catch on widely. We ended up having only about 35 reels of music, and the obsolete recorder/player is still mounted in our hi-fi cabinet.

In the early 1980’s Sony introduced the “Walkman” portable stereo cassette player in the United States. Of course, everyone had to have one. The first introductions in the States were expensive and our children were still young. But it just so happened that Bette and I were going on a vacation in Japan and we thought that we could get a good buy there. After gathering courage to use the Tokyo subway system, we managed to find the Akihabara district in central Tokyo, famous for its many electronics shops. We bought three Walkman that were guarantied to play in the US. They did, but, perhaps because these were early technology models, they were soon superseded by more light weight and reliable models.

We completely missed the 8-track cassette mini-boom. This boom was probably short lived because it was developed under the impetus of the Ford Motor Company to be used in automobiles. Use outside of automobiles did not become widely popular.

Soon analogue technology was replaced by digital technology and there was a mass movement to CD recordings. Compact, stand-alone CD players quickly became available and our home acquired a “quality player” for serious music listening as well as CD units as part of boom boxes and radio/CD combination players in various rooms.

However, that was not the end of the pursuit. MP3 technology came on the scene via computers and soon we were able to hear high quality music from devices no larger that a cigarette lighter or a thin stack of playing cards. These latter devices also can show photos and short video clips.

And finally, even radio has gone digital. We now have an HD (high definition) FM radio, probably the first of many as we will one day be urged to replace all our radios with this latest technology.

What’s next?

A related link (mentions 78 rpm records):
Fantasia, Toscanini, and Music in the Air

No comments:

Post a Comment