↑ TheIntercom
Page Created: 7/28/2014 Last Modified: 5/1/2018 Last Generated: 10/22/2024
I used to read 1960's era science books when I was around 6 years old. The books were already old by then (1976) and were from the dusty attic of the private school where my grandfather taught. He would let me read them at home. The attic was a fascinating place where old class projects from students of years past were still there, untouched. I remember seeing a Styrofoam solar system display with painted planets on rods.
In one of the books, they showed children talking to each other using tin cans and string; the string would carry the vibrations of the sound wave to the other can. I also remember seeing an illustration showing children who were neighbors across from each other in two urban apartment buildings (several stories up) passing paper messages to each other over a rope and pulley system.
The idea was fascinating, a way of communicating without using the telephone.
When I got older, I had a neighbor in the suburbs two houses down, and we couldn't always use the telephone to call him, especially late at night when our parents thought it was too late to use the phone. We could not afford walkie-talkies, and even so, you could not keep the cheap ones turned on for long since they were noisy and the 9-volt battery drained fairly quickly. So I tried to devise another system to communicate.
I realized the tin can idea was impractical at those distances but got the idea that we could use string to deliver written messages to him. He lived in a two-story ranch-style house, his bedroom window was up in the air. We lived at ground level, also a ranch-style house, and there was a one-story neighbor who lived between us.
So I got the idea to scale up and attach screw-eyes into the trees at the level of his window, raising the string up into the tree, over the neighbor's house, and into his bedroom window. I was too young to know much about pulleys (and they were expensive), so I used screw-eyes.
This string would then loop back to where it originated. To send a message to each other, we would insert the message into a plastic capsule on the string and pull the opposite string to move the capsule into the tree tops and over the neighbor's house to his window. We installed bells at our windows so that if the capsule hit hard enough, it would ring the bell.
It was the first engineering adventure of my life, like creating the bridge to span Niagra Falls. I tied an apple to some kite string and threw it over the neighbor's house, then tied more durable, thick monofilament fishing line to the string and pulled the fishing line over. I then climbed the trees (there was a tree conveniently by both of our houses) and ran the line through the screw-eyes in each tree, then each window, and back to the original house. Then I tied the ends of the fishing line together to create a loop. The friction of the fishing line against the screw-eyes was low, so this seemed like it would work.
And it did work. It took a long time to pull the string until it reached the other house. You would see the little capsule go up into the tree and over the neighbor's house, a little piece of paper in mid air...
Now the drawbacks: we got tired of pulling the string.
I can hear Bela Lugosi shouting Pull the string!
Since the whole reason we did it was to communicate late at night when we couldn't use the phone, we had our windows open without the screens at night so we could get our arms through to pull on the string. I forgot to plan for one thing...
Mosquitoes.
I hate mosquitoes to this day.
The rooms got infested with mosquitoes since we had to have our windows open for so long. Needless to say, we got tired of using the system pretty quickly.
I later bought some intercoms at Radio Shack for $15 and fantasized about connecting these between our houses. But it was hundreds of feet to the neighbor, and I could not afford that much wire. And the wire it came with was very thin, so the resistance at distance would be high, and I wasn't sure if it would work.
Then, one day, my neighbor's older brother mysteriously appeared and delivered to me the most wonderful gift. He threw a big coil of hundreds of feet of wire at my feet and said I could have it. It was old, used wire he got from some kind of home rehab project he was working on, and it was good, heavy-gauge, solid copper wire.
I immediately ran that old wire to the neighbor's house. I got permission from the neighbor between us to run it along the fence in his yard (but didn't realize that it wasn't actually his fence), and as I was installing it on the fence, a lady (another neighbor) shouted at me to stop, saying that I could electrocute myself. I yelled back at her telling her it was low voltage and she didn't know what she was talking about, and that I had permission. She complained about calling the electric company and went back inside, but she never did.
I ran the wire up into the trees again and over to our windows where the old screw-eyes were still in place, and the system worked well for months. I never thought about lightning, though, and never grounded the system. I had a ground rod outside that I used for one of my radios, but I never thought about using it for lightning.
But lightning never hit it, and it worked so well that we got tired of being interrupted by each other. It was like a person texting you a lot--it quickly gets tiring responding to them.
We would be sleeping and our neighbor would buzz the intercom and wake us up. It was a loud square wave: buzz, buzz, buzz. That buzzing was grating on our nerves, and it was getting to our neighbor as well.
That's when I realized that people don't always want to communicate with each other. People need separation but the potential to communicate.
I later tried to improve on the idea by creating a full-duplex intercom by using two sets of audio equipment (microphones and speakers at both ends) so we could have more of a telephone-like experience (since the intercom wire was still in place), but we kept getting audio feedback. I then learned what feedback was and it set me on a quest to learn more about telephone electronics so I could counter this, but months later, I took the system down.
I eventually cannibalized the circuit board containing the amplifier from the main unit to use years later in ThePhoneSystem, which is why the picture above is missing the button. But I couldn't get myself to throw them away. We had a lot of good times with those intercoms.
Years later, those screw eyes went unused, rusting up in the trees as the bark began to grow around them. Sadly, those houses and trees that carried the messages are now gone, the grassy lawns lay buried under the Lambert airport runway.
