Digital TV So Far Not So Good

The transition of the broadcast stations to Digital TV has not gone smoothly despite the delays, subsidies, millions of messages and public service announcements. Nielsen has estimated that 2.8 million households are still totally unprepared. There are households that were unable to get the government coupons because there were no coupons available, households that were told they were not eligible for the coupons, and still other households who couldn't afford the boxes even with the coupons. There are also households that don't seem to care about the loss of broadcast TV.

Locally there is one household that bought two converter boxes, without the aid of the hard-to-get coupons. Did this solve all the problems for these people? Oh, contraire! Two converter boxes leaves this family four boxes short, so now they have four TVs that are only fit for video game use or recycling as boat anchors. One of the converter boxes continually drops channels which it fails to find on their small, indoor antenna. Thus, entire evenings of programming are sometimes lost through the whims of the converter box.

This family also cares for the wife's elderly mother, onto whose TV the other converter box was connected. She continually gets confused about which remote to use. The error is easily detected when another family member is in the living room and suddenly hears white noise begin to blare from the old lady's room, at which time a family member must go in and set the situation right once again. It is also reported by this senior citizen that her box keeps turning off spontaneously. Whether such is actually the case, or whether the problem is entirely rooted in operator error the family has yet to determine.

All of this expense, at $60 per box and $28 per antenna, was visited upon this family without their consent. They didn't get to vote on it. They lost a lot of cheap entertainment and regained very little of it. The government, in the guise of the Federal Communications Commission (FCC), tells us the change was necessary to free up more bandwidth in the communications spectrum for first responders. I find this to be a curious reason since what I learned of signal propagation during my time in the military taught me that the bandwidth of a signal is inversely proportional to the smallest effective pulse duration the signal uses, i.e. the smaller the pulse duration, the higher the bandwidth. Now we are talking about digital encoding of television signals which is going to squeeze even more information into the same 6 MHz of bandwidth used by the now defunct analog signals.

This requires signals to be compressed. This causes smaller effective durations of information (pulses) which, in turn, should raise the bandwidths. However, the Advanced Television Systems Committee (ATSC) decided to go with a system that can have up to a 55 to 1 reduction in the bits of information that actually make it from the transmitter to your television set. Hmm! Still 6 MHz per channel, even more channels and a big loss of signal information? Just what was this big change all about then?

For one thing, it will move the bandwidth used by television signals to another part of the frequency spectrum since the carrier waves used for digital signals are far different from those used by analog signals. Another reason for the change was, in part, a bailout of sorts for the television industry. Since the late sixties, television networks have basically been broadcasting on two separate networks.

They sent out analog signals to Mr. and Mrs. Public and digital signals to the cable and satellite companies. What do you think that cable box on your TV has been doing all these years? It has been converting digital signals for use by your analog television. This is why folks who already have cable or satellite service didn’t need to buy converter boxes to keep getting the broadcast channels. All that was needed for this final switch was to build converter boxes for the folks who don’t or can’t pay to watch TV. What they also didn’t tell us is that digital transmissions are very susceptible to atmospheric attenuation.

The moral of the story is that this switch to digital TV had more to do with convenience for the broadcasting networks and an en masse shift of their signals to a different part of the electromagnetic spectrum that could allow the change to be nuanced as a boon to our friendly fire and police professionals. So the next time you get pixellated transmissions because of a thunderstorm on the night you were hoping to find out who won America’s Got Talent, buck up and know that you’re doing your part to make our country safer! Then you can turn off the set and go play Parcheesi!