Setting Up Your Antenna

There are some differences between the analog and digital signals that can make a difference in how you set up your antenna and this concerns antenna amplifiers and signal strength. In the analog world, more is generally better. In the digital world, enough is all you need.

While nearly any decent antenna used for analog reception will work for DTV, the same is not necessarily true for amplifiers. The reason is that the DTV signal requires extremely linear amplification, more so than the analog signal. Non-linear amplification introduces distortion into the signal. Analog is more forgiving than digital. Excessive non-linear distortion of the DTV signal appears as bit errors to your receiver. If the errors overpower your receiver’s error correction capabilities, you get either no picture or severe picture blocking and stuttering.

Using An Antenna Amplifier

Your DTV receiver requires only enough signal to allow its error correction circuitry to function properly. Any signal above that is not used and will not improve the picture quality. Your DTV receiver has some sort of signal level indicator. Generally, this is a computer-generated number that is a combination of the actual signal strength and how hard the error correction circuitry is working. If the signal level is high, but the error correction circuits are working very hard, the value will be lower than if the signal level is lower but the error correction circuits are doing less. You should check your owner’s manual for details on how your DTV receiver calculates its signal level. So the trick is for your antenna to deliver enough distortion-free signals, but not too much.

In general, there are only two reasons to use an amplifier: you are far away from the transmitters and even with a large antenna, the signal level is too low or you are distributing the signal to several rooms in your house and you need to compensate for the cable loss or both.