How Powered TV Antennas Boost Signal and Why TV Sets Can't Amplify Signals Themselves

When it comes to improving TV reception, powered TV antennas are a popular choice. But how exactly do they work, and why can't TVs simply do this themselves?

What Makes the Best Antenna Booster?

The optimal antenna booster is one with substantial gain. Enhancing signal strength is crucial, but it's important to understand that not all amplifiers are created equal. An amplifier can introduce unwanted noise, which can degrade overall quality. This is particularly problematic with digital signals, where the quality is just as important as the signal strength.

When placing an amplifier near the antenna, it can amplify the extraneous noise picked up by the cable. Therefore, if you need an amplifier, it's best to place it close to the antenna. This minimizes the noise.

Splitting the Signal for Multiple TVs

When dealing with multiple TVs, you may need to split the signal. In such cases, a passive splitter is typically the best choice rather than an amplified one. However, if your setup requires an amplifier, it should be placed at the TV end, assuming you have a sufficient signal to start with.

Amplifying the TV signal can sometimes have the opposite effect of what you're trying to achieve. Weak signals may become receivable, but strong ones can overload the TV’s inputs, leaving you with a blank screen. This is especially true in digital signals, where the data is partly in the amplitude area of a phase shift.

TV Sets' Built-in Amplifiers

TV sets come with built-in amplifiers, but these are not typically of the best quality. The best way to achieve the lowest noise floor is to place a low-noise amplifier near the antenna. The old AM VSB NTSC signal had a low noise floor of -59 dBmv, with a minimum usable signal of -20 dBmv. However, with digital signals, it's likely this noise floor is even lower, but by only a small margin.

Where to Amplify the Signal for Optimal Results

Amplifying the signal closer to the antenna can yield better results, as the signal tends to be cleaner at that point. If the signal is prone to interference, amplifying it closer to the TV tuner can amplify the noise as well. Placing the amplifier near the antenna can help mitigate this issue, ensuring that the signal remains clean and noise-free.

By understanding the principles behind amplified TV signals and the best practices for placement, you can significantly enhance your TV reception without compromising the quality of your viewing experience.