For good or ill Television has had a major impact on society. Unknown to many television had a brief flowering in the form of mechanical systems in the 1920 and 1930's which died when Cathode ray tube electronic television developed. The common explanation was that mechanical television was too crude and unwatchable to survive. But like the obsolete idea that the dinosaurs died out because they were too stupid too keep mammals from eating their eggs this explanation doesn't fit the facts. This post asks what if some bright inventor combined many of the ideas that were available at the time to make a mechanical television system that could survive and grow, perhaps slowing the development of the electronic tube television systems that dominated the next 50 years?
This premise is based on the science and engineering that was known at the time and has no supernatural or extraterrestrial elements.
The well dressed man paid the taxi driver and looked around the Boston neighborhood. It was modest but well kept with nicely trimmed lawns. He pulled out the card from his pocket to verify where he was going. Yep this was the place. He felt some relief. Often the people trying to interest him in new inventions lived in shabby hovels, their workshops squalid messes.
Now with the market crash things were getting even worse. He’d given up seeking new ideas for his television business from such people. So many would be inventors were desperate to make money on any little idea no matter how silly or impractical.
The only thing that brought him here was the tiny electric valve device that had been included in the letter he’d received from this man. Hollis has spent hours experimenting with the valve with growing excitement and amazement. No bigger than a quarter, it functioned like a vacuum tube but required only a fraction of the power to operate. No need for a cathode heater, no warm up time. Just connect it to an electric current source, apply a bias voltage to the ‘gate’ as it was called and current flow could be precisely controlled. Incredible!
Granted power output was low for the small disc but Hollis suspected that this was just a demonstrator. And if not it could still replace many of the tubes in the front end of a radio amplification circuit, assuming it was inexpensive to make and reliable. The engineer looked at the attached card.
On top the logo read Tectronics the dramatic sweep of diminishing letters forming an arrow shape under the extended T. Under that logo was a name: Robert Palance – Inventor, along with the address. And at the bottom was a motto:
“The Future Is Now.”
He flipped the card over and read, “Mr. Baird, I believe you may be interested in some ideas I have for the improvement of television. Please come see me. Bob.”
The home was well maintained and larger than most of the others around it, many with for sale signs, sadly common today. Hollis noted a sizeable garage/workshop in the back yard and a delivery truck in the driveway. There were two sets of power lines going to the residence. Presumably whatever was being done there required quite a lot of electricity.
He walked up to the front and rang the doorbell. A maid answered. “Yes?”
“Hello Miss. My name is Hollis Baird, chief engineer of the Shortwave and Television Corporation. Mr. Palance…”
The maid smiled, “Of course Mr. Baird! Robert has been expecting you. He requested I direct you to meet him in the back workshop. Just ring the doorbell and he’ll let you in. I’ll announce your arrival through our internal telephone system.”
She pointed to the walkway to the left. “Internal telephone system?” Baird thought.
Hollis followed it past the delivery truck and to the front of the workshop. To the right of the wide garage door was a button with a large sign that said Press for Entry.
The chief engineer did so and was startled by the sound of motorized gears as the garage door slowly opened. A man in a white lab coat with a broad smile on his face strode out to meet him hand outstretched.
“Mr. Baird. What a delightful pleasure to meet you! I’m Robert Palance though you can call me Bob if it pleases you. I’m so glad you finally made it to my little lab. Do please come in.” The inventor waved the engineer into the workshop.
Hollis took a step in and allowed his eyes to adjust to the relative dimness. He’d been in enough of these places to be cautious of tripping over some carelessly thrown bit of junk on the floor. But in this case the room was well lit with overhead lamps and all equipment was nicely put away leaving the spaces between the two rows of tables clear. There were two workers in white coats in the back installing electrical components in a box. He noticed more familiar rectangular wooden boxes on the tables with their unmistakable square viewing chutes and shadow box collars with optional 6 inch lenses for expanding the one inch square image that the units were capable of displaying. Next to each were the wooden boxes of the associated shortwave receivers.
“I see you have a fondness for our Model 36 televisors, two of them!”
And he pointed to the third console standing next to the table on its spindly legs, “And a Model 135C as well.”
The model 135C was simply the 36 model placed in a nice upright cabinet along with the short wave receiver electronics in one convenient package.
Bob smiled, “Yes I’m a fan of your elegant design. You put a lot of thinking in your televisor and it shows. Convenience, cost, and reliability, I congratulate you.”
“But why three?”
“Well as soon as I saw your televisor I realized your company was the one I wanted to work with. Many of the televisors on the market are little more than jumbles of parts around variations on the Nipkow disc. Your belt system, while not original, allows installation of a horizontal scanning process in a nicely enclosed box which is perfect for my purposes. That, along with your phonic synchronization and short wave receiver, has provided an ideal platform for my refinements.”
“Which are?” Hollis asked intrigued.
Bob moved over to the closest televisor and put his hand on the smaller box on top of the televisor. Hollis had noticed it but figured it just held tools.
“This is one of them,” The inventor then pulled out something wrapped in cloth from his coat pocket. It was a thin black disk with a hole in the center. It looked like a small phonograph record but a segment had been cut out. He held the disk up to the light. The cut out section had a reflective surface. The light from the open door flashed off the mirror edge as he turned it back and forth.
“Using a small record press I make these from a shellac and carbon formula. I then chrome plate the cut out section with a special process. I usually do a set of 48 pressed together to insure uniformity of the reflective surfaces.”
Bob then opened a door on the side of the box. Inside was a stack of the disks arranged in a helical pattern, each mirror edge slightly offset from the one above and below it.
“I put a set of these on a spindle and glue them together in a precise screw arrangement to form a complete 360 degree twist. The device is connected to the shaft of your belt spider through a hole drilled in the top of your televisor. ”
“So each reflective edge represents one scan line reflected from a modulated light source as the assembly turns.” Hollis added with growing understanding. He pointed to the left of the door.
“And this must be where the modulated light source is kept. A neon lamp?”
Bob held his hand up, “Yes, but it’s not neon. One of the problems with modern televisors is that modulation and light are combined. The result is that light intensity and quality must be compromised. The dim reddish neon glow is just not conducive to good televisor viewing. My light is simply a simple incandescent lamp though a high pressure mercury vapor lamp is something I’m experimenting on. High intensity and a long life. “
He opened a smaller door in the wood frame exposing the modulating apparatus. “The modulation is performed by two thin steel blades set opposite each other to block the light source. Behind them are electromagnets that cause the blades to vibrate in response to your unit’s modulating signal allowing light to pass between them in proportion to the intensity of the signal. The rest is just appropriate lenses to produce a vertical line of modulated light to reflect off my mirror helix. Simple.”
Hollis held up a finger, “But is the response time of a mechanical system adequate?”
Bob smiled wanly, “I admit it took some time to get this system working properly. With the 15 to 20 frame per second, 48 to 60 line televisor broadcast systems that are common today it seems to work fine. For faster frame speeds or higher line resolution, well I’m investigating the use of piezoelectric crystals with mirrored surfaces. Or just varying their refractive indices. Rochelle salt and quartz are most promising materials. We’ll see.”
Bob closed the modulator door and turned on the unit, “Here let me give you a demonstration. I was working with it a few minutes before you arrived so warm up time won’t take too long. I’ve replaced some of the vacuum tubes in your amplifier circuit with my electric valve wafers which should reduce warm up even further. Did you try the one I sent you? What do you think?”
“It’s the reason I’m here. Your own invention?”
“Yes though I derived some inspiration from the work of a gentleman named Lilienfeld. Met him in Germany while at university and have kept up correspondence since. But while he studied copper compounds my interest was in photoconductive materials such as cadmium sulfide and selenium. That’s how my fascination with television developed.”
Hollis nodded, “If you can manufacture those valve wafers in quantity the Shortwave and Television Corporation will be happy to arrange for their distribution and sale through our commercial…”
The hum of the televisor had stabilized and a warm white glow was emanating from the mirror helix. Roughly five inches across the spinning rectangle of light was certainly easier on the eye than the dull red glow of the one inch plate of the Kino bulb in a standard Hollis Baird televisor. No need to find that right viewing angle through a thick lens. Nor any need to darken the room.
Bob adjusted the frame lever and did some final tuning with unfamiliar knobs that had been added to the televisor. An image stabilized. Suddenly a flash of awareness came to Hollis.
“Wait a minute! This isn’t a televisor transmission from our radio station.”
“No,” Bob agreed. “W1XAV doesn’t broadcast until later this afternoon. This image is coming from the unit itself.”
As if to verify that he passed his hand in front of the original viewing chute. The hand appeared immediately on the spinning mirror helix. There was an ethereal look to it almost as if it was floating in the center of the device.
“My God!” Hollis gasped. He thought about the massive electric arc scanning machine in his company television studio and the wall of photocells and attendant amplifier needed to produce the simplest television signal. And how uncomfortable it was to stand in front of all that machinery. “How are you doing this?”
Bob smiled again. “That’s the next refinement I’ve made.”