THROWBACK THURSDAY: TURNING ON, TUNING IN...
UNM CAMPUS--Tucked into the underground cavity that is called the Centennial Science & Engineering Library, the Depew radio collection is seldom seen and rarely discussed. But this collection of radios just might embrace the most dramatic five years of Geekdom ever assembled. The years 1921 - 1926 were the seminal years for the development of vacuum tubes, laying the groundwork for not only radios and TVs, but transistors and other semiconductors, and even computers.
I do love tube radios. Before MaryAnn moved in I had 40 or 50 radios just in the living room. The bedroom had another couple dozen. And another 30 or 40 lined shelves in the basement and garage. But, things being what they are, to make room for MaryAnn I traded a pickup load of radios for a pickup load of firewood. And without complaint or regret. Still...radios draw me in today just like the radio shows did when I was a boy. Almost every night my brother and I would sit in front of the kitchen counter listening to those wonderful radio dramas and comedies: Fibber McGee and Molly, The Lone Ranger, Yours Truly Johnny Dollar, The Shadow, The Great Gildersleeve, and I Was A Communist For The FBI. You just had to sit right in front of the radio!
The Leo Depew Collection
I thought I better take someone with me to view the radio collection, someone to help me understand what I was looking at. So I Googled around and ended up at the New Mexico Radio Collector's website and eventually contacted Bob Avery. Bob had been a friend of the late Leo Depew but had never seen the collection after it had been installed in the library. We met and walked over to the Centennial Library, an underground facility with only a small glass facade above ground--barely large enough for the staircase leading downward. The collection is right at the bottom of the stairs.
Bob Avery and I were both soaking wet at this point, having walked in the rain for quite a ways. I took off my wet jacket and threw it in the corner. Bob started talking. The first thing that caught his eye was an Atwater Kent breadboard. All the tubes and parts are elegantly visible on a wooden base resembling a bread cutting board. The silver tubes and brown bakelite dials gleamed like jewels, even in the dark cabinet. I could only imagine what they looked like on a dark winter evening all lit up...reflecting off the ceiling as the family sat in silence around it. The year would have been 1924. Its price at its introduction--$85.
Eighty-five dollars was a lot of money in 1924. But there was a much cheaper and simpler way to listen to the radio: the crystal set. Crystal sets require no power source, no tubes, and can be built at home...although the crystal sets in the display are commercial models. By the way, tubes themselves were quite expensive at that time, five to ten dollars each.
Crystal sets use a piece of galena crystal to detect the radio waves. A sharp piece of wire called a Cat's Whisker is poked into the galena until the signal comes in good. The crystal sort of acts like a one-way valve and lets the radio wave pass through without feedback to the earphones. Earphones were necessary because there is no signal amplification due to no power source in this kind of set. There is also a coil of wire that functions as a tuner. A metal arm or slider moves across the coil of wire. This lengthens and shortens the amount of wire in the circuit. What this does is tune in various stations by matching the length of wire to the wave length of the station. The crystal set picks up the signal through a kind of resonance...something like a pair of tuning forks that vibrate together even if only one is struck. Besides earphones, a crystal set needs a long antenna...maybe 50 feet of bare copper wire stretched outside like a clothesline with insulators.
I made a crystal set myself when I was a boy. It was quite a thrill, even if it only got one radio station. I'm not sure if it would mean much to kids today. Crystal set kits are still available at places like Hobby Lobby. They use a diode instead of a raw piece of galena, but the concept is exactly the same.
Bob Avery pointed to a rather plain looking set from 1922. "Crosleys were the Model T of radios," he said. "What other companies were selling for $200 Crosley sold a comparable set for $30."
"Would you call them elegant or crude?" I asked.
"I'd call it simple...functional." He pointed to a beautiful set made by Grebe. It had a wonderful wooden case with a painted bakelite front panel. A multitude of dials and peepholes allowed for plenty of fine tuning by the listener. And it was a whole lot prettier. Radios were going in two directions at this point. Some manufacturers were making radios that resembled pieces of furniture, others like Crosley make utilitarian table models that weren't so nice to look at.
Crosley outsold many of the other manufacturers, but wasn't making much money because of his low prices. At some point he abandoned his commitment to inexpensive models and decided to spend more on cabinetry...just in time for the onset of the Great Depression. In this sense, the "Henry Ford of Radio" looked somewhat like the Ford Motor Co. of today.
It didn't take too long before radio geeks figured out how to amplify radio waves to the point where they could be heard with loudspeakers. Some early speakers are part of the display. The celluloid horn speaker is particularly interesting. How that delicate instrument survived for over 80 years is amazing.
Amplification led to the use of vacuum tubes: one as a detector and the rest to amplify the signal. It is pretty complicated for a neophyte like me to explain, but I included a photo of the explanation from the display that can be clicked on for more information. Basically there were three types of amplified receivers: regenerative, tuned radio frequency (TRF), and superheterodyne.
Early radio sets required batteries for the DC current they used. The batteries were expensive and large. A typical set might need 3 different batteries ranging in voltage from 1 1/2v. to 90v. What a lot of work to keep all that running.
The first commercial station in America is generally agreed to be KDKA in Pittsburg. It started broadcasting in 1921. However there were many amateur broadcasters with home-brew transmitters before then. Also, ship-to-shore transmissions were available to many listeners. The point is that receivers and transmitters sort of developed at the same time and were designed and built by a lot of people that were not too different from you. There were radio manufacturers and developers in every garage back east.
Sales brochures from the period offer a glimpse at just how magical and enticing these early broadcasts were. Listen to this ad from the Atwater Kent company concerning the 1926 election: "This is going to be a radio campaign. Travel to Kansas City and Houston at the speed of light and at a cost of only a fraction of a cent an hour. Sit up on the platform with the orators. Get down among the delegates and hear the voting. Listen to the bands, the singing. Have at your side a man who knows what's going on every minute and will tell you what it means."
How much we take for granted today.
If you are planning on visiting the Centennial Library you are better off taking a bus than looking for parking. The Rapid-Ride stop is only about a block away. Here's a map to help you find the building.