Sunday, March 3, 2013

Old Radio



Today's picture shows an early radio receiver. The device was self contained, and capable of receiving a signal from across the country. You can see that the device is based on seven vacuum tubes and the bottom half is filled with batteries. A vacuum tube was a very early electronic component that could act as a switch or an amplifier. They used lots of power, and burned out frequently. In the 1970's the vacuum tube was replaced by the solid state transistor. A transistor could do all the work of a tube as a fraction of the cost, low power and they did not burn out. Using transistors miniaturized electronics for two reasons. First, the transistors themselves are small, and second, since they dont use much power, the need for huge batteries was reduced. For comparison, modern computer chips can have in the neighborhood of 10 billion transistors.

13 comments:

  1. Replies
    1. True! Despite decades of technological advances nothing beats the sound of an old tube amp for guitar.
      John

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    2. Yes because the tube gives a smooth wave where the digital version immitates a wave by a "stepped" wave.
      The best equipment still uses tubes.

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  2. It is amazing how far we have come. Neat photo.
    -Anne K.

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  3. Wow... neat picture.

    I wonder what it would cost to replace all of those batteries? They sure would make the radio expensive to run... a true luxury at the time I am sure.

    Graham in St. John's

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  4. It's interesting that a radio would have a microphone, or at least that's what I think that device is in the lid.

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  5. That's a 'horn' speaker. The sound producing element is small, like half a pair of headphones. The arrangement amplifies the sound.

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  6. Ah, remember when most hardware stores had tube testers? You brought in the tubes from your radio or TV and plugged them in, one by one, to find which has burned out. My very first kiss was beside one of those. I was so startled that I lost my balance and nearly knocked over the machine. "Hey! What are you kids doin' up there?" Just leaving, sir, just leaving.

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  7. Oh - in case you are wondering, we had come into the store to get out of the cold while we waited for the bus. That's my story, and I'm sticking to it!

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  8. A story that my late father used to tell from his childhood in the country side. No electricity, so every few days someone would take the radio batteries and take them (on horse back) to a nearby mill which had a generator and could recharge them. He always cracked us up with this story of one uncle of his who would yell as the rider was leaving, "and this time make sure you put more music and less talking on those darn batteries" :)

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  9. I have a couple of Zenith Transoceanic radios that were quite popular and expensive throughout the 40s, 50s and 60s. Those were the tube radios and they did , indeed, sound very mellow. By the 70s Zenith changed from tubes to transistors and the quality of the sound suffered slightly. Unfortunately, the arrival of the small portable radios spelled the end of the big radio and they have become collector items.

    The two I have are the first one with transistors and the final production year and they sound excellent. Now if the collector market will rise, I could sell them to a good home.

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  10. I remember working in a TV and radio shop and had to sort the tubes as a young girl just starting to work.

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  11. I love old radio programs. I listen all the time via podcasts.
    Today, I was thinking how we used to watch TV. Buy a TV and watch for free as long as the TV works. Now we buy a TV that is outdated before we purchase it and we're lucky if it makes it past the flimsy warranty. Plus, we pay crazy high monthly bills to cable or satellite companies to watch programs with commercials. Some of those channels we on't even want. Crazy.

    Hope radio continues to have free airwaves. Just wish there were more quiz and cereals to enjoy. I would be happy if we had a modern day Paul Harvey giving us short The Rest of the Story stories. I look forward to this week.

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