Remember the days before cable television when someone in the family
would assume the job of antenna contortionist? To improve that ephemeral
picture to a viewable standard, they would skillfully adjust the alignment,
length, and altitude of the antenna to get the best possible picture.
But sometimes the picture would still show a foggy double image or ghostly
images from the next channel. All these problems are caused by the weak
signals from distant or blocked transmitters.
A basic natural law that our technology can't overcome is the weakening
of television signals as they travel away from the transmitter and around
or through objects. Both analog and digital signals get weaker with
distance. However, while the picture on an analog TV slowly gets worse
for more distant receivers, a picture on a digital set will stay perfect
until the signal becomes too weak for the receiver to pick it up. By
perfect I mean the picture on the TV is exactly the same picture the
broadcaster started with at the transmitter. In a digital signal, a
one is always a one and a zero is always a zero.
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