REBOL Technologies

Analog TV era ends, DTV begins, complexity thrives

Carl Sassenrath, CTO
REBOL Technologies
15-Jun-2009 19:41 GMT

Article #0411
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Across the USA at midnight, the era of analog broadcast television ended. It lasted more than 60 years. Quite an achievement for any technology.

I must admit, I have mixed feelings about this "advance" in technology.

A bit nostalgic

Sure, I'm somewhat nostalgic about the television business. I began working in TV at the age of 13, when I saw an announcement on a local PBS station (KEET 13), asking for volunteers. I rode my bicycle (because I was too young to drive) down to the TV station, and told the general manager, Don Telford, an older gentleman in his 60's, that I would like to work at the station.

The manager looked at me over his eyeglasses, asked a few questions, then took a huge risk: he made me a "switcher" -- the person who runs the master control that puts programs on the air. He was a trusting man.

It was a great job, and I loved doing it. After two weeks, he called me back into his office. "You are no longer a volunteer, " he said. "We are hiring you as an employee to run the master console every day."

Two years later, at the age of 14, with the PBS experience as leverage, I managed to get a job at the ABC network station as a cameraman and film developer. And, thus began a passion for TV, including every facet of the business... from live news production, commercial production, film, video, engineering... I could not learn fast enough every job and opportunity at the station.

A few years later, when I finally left to attend the university, I had worked my way up to the top production position at the station: director of the 6PM news, a live production that required fantastic concentration and timing.

Understandable, therefore fixable

One of the things I liked about those days is that you could learn, understand, participate, and contribute to every aspect of the technology and art.

For example, when I was 14, working at PBS, the stations main color TV camera (large complex devices back then) stopped working, and had been pushed into the corner. The engineers told me something major was wrong, and it could not be fixed.

Never being one to be discouraged, I worked on the camera during the less busy times of running the master console. Alone, using an oscilloscope, I worked on the camera for a several weeks, tracing the signals through the various subcomponents of its video circuitry. I finally discovered that the primary drive transistor for its cathode (the source of electrons for the beam that captures the image) was burnt out. A quick replacement, fixed the camera, and the station manager was delighted to have the color camera back on the air. (Rather than black and white).

Anyway, I have a point here, beyond just the story. My point is, the technology, even in it's more complex domains (inside a TV camera) was understandable and workable. It wasn't beyond our grasp, as even demonstrated by a 14 year old boy.

The same is not true for DTV. The modern digital world consists of several higher level components built on lower level technologies that are, frankly, extremely complex.

While the complexity offers us nice features and capabilities, such as HDTV with Dolby 5.x sound... it removes us from the inner workings of the system itself. The result is, it becomes much more difficult to debug, and in some cases nearly impossible to work on.

There is a hidden cost

Sure, the DTV signal produces a great result; however, the cost of that result is that the signal and its processing is much more prone to ultimate failure. It's not a free advance. It comes at a cost -- one that's not so obvious.

Some of you will challenge my statement, but I have a good example to prove my point.

As a community service I volunteer a small amount of my time to help bring free over-the-air TV channels to the remote community where I live. On top of a nearby mountain we "capture" the distant signals from San Francisco and rebroadcast them to the town. The term is "translating". We run a series of "translators" that you can think of as repeaters or boosters.

When TV was analog, these devices were fairly easy to understand and debug, but most importantly, they were robust. An analog signal consisted of three "carrier" frequencies that were modulated (AM and FM) with the content's video and audio. You could easily detect these signals, and if the signals degraded from interference or loss of signal strength, the content would still be "watchable". It might contain a bit of noise (static) or lines, but a viewer could still follow the program.

Now, with DTV, you get either a perfect picture or not. It's either on or off. It works or it doesn't.

And, what's worse, is that when it doesn't work, it can be quite difficult to figure out what's gone wrong. The signal can be too weak, too strong, distorted in some way (e.g. multipath), or interfered with (from some other signal).

In addition, the DTV modulation itself is quite tricky to even detect with a simple device. If you look at a DTV signal with any analog device, you see noise. If you want to really examine the signal itself, you need an expensive device that is able to recognize the signal and help you debug what's going on. Of course, our small TV organization cannot afford the cost of such a device, so most of the time, we can only guess.

Enslaving ourselves

Although, I'm commenting here about DTV in general, what I'm saying applies to almost all modern technologies. It doesn't matter whether it's a DTV transmitter, enterprise server to run the local college, or even the metering device on your water line. We rarely stop to ask if the complexity involved is worth the benefit.

In a very subtle way, we are enslaving ourselves to our technology. We are allowing layers and layers of additional complexity that far exceeds the abilities of most human "intuition" and "comprehension".

Many years ago I predicted the economic collapse we are now experiencing worldwide. My prediction was not based on specific details of operation, but on the higher-level acceptance of complexity as "standard operating practice." When I saw friends graduating from MIT to work on Wall Street algorithms, I began feeling quite nervous about the future of our investment banking systems. Why? Because I knew that the executives and decision makers who ran these giant corporations would "blank out" and not understand, or even attempt to understand, how these systems work. And, as a result, without an engineer in the locomotive, we'd begin to see these trains begin to derail at every turn.

When we separate ourselves from the systems that work on our behalf by adding layers and layers of complexity, we are ultimately doomed to fail. This applies to all domains, from insurance companies to medical systems to space vehicles to entire governments.

The reason is quite clear. We (as humans) exist within a narrow band of comprehension and intuition. Once our systems grow too complex, we as humans no longer possess our essential "gut intuition" nor any idea at all how our monster system will react to unforeseen situations.

Of course, this is one reason why I've taken a different direction in computing. But, you already know that. However, a lot more needs to be said about it.

Anyway, enjoy DTV. It really is a nice picture. But, good luck figuring out that it is a harmonic mix from your neighbor's microwave oven that is glitching your HDTV football game or favorite movie.


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