Most satellite television menus will provide users with some sort of measurement of the signal they are receiving. In most cases, this will be displayed in terms of “Signal Strength” and “Signal Quality.” But what do these terms actually mean? Can you alter them? Moreover, what impact do they actually have on the quality of the picture on your television set? As TV Aerial Installers in Preston we will attempt to clearly explain what the difference is.

Before we begin this discussion, it’s important to note that all televisions and television services are different. Not everybody will be able to find a reading on their signal’s strength or quality, and some will only see arbitrary numbers or percentages that seem to have no meaning. Still, regardless of what is displayed, it is still helpful to know what this information means for your signal.

This is Just a Guide

​Whenever I install aerials or satellite dishes, I use a device known as a Horizon Meter. This meter provides measurements on signal strength, potential interference, and more. I mention this because the signal measurements that you get from this device are far more accurate then what you will find in your television or satellite menus. So while you can technically get some information from these sources, you should take it with a grain of salt until you use a device like this.

Televisions Don’t Provide Enough Information

​One of the biggest issues with the signal readings you get from your satellite box or television is that these devices don’t tell you how they’re reading and measuring the signal. As I mentioned, you’ll usually only be given a percentage, signal bars, or a set of numbers that are meaningless unless you know how to read them. This can lead to a lot of misleading results and cause a lot of confusion as to why you might not be getting everything you paid for. In some cases, TVs will give you a Bit Error Ration (BER), which is far more useful than the generic data other models offer.

Having 100% Signal Isn’t That Important

​The problem with signals that are presented as percentages is that signals aren’t measured this way. This means that whatever number you see is practically useless as far as conveying information. If you see a signal rating of 100%, you might assume there is no room for improvement on the signal, but this isn’t true. You can always get a stronger signal by installing a TV amplifier or high-gain aerial. Of course, doing this arbitrarily – without consulting a professional – can lead to having too much signal, which can overload tuners and equipment and make your signal worse.

The Real Focus Should Be On Quality

​You should always expect your TV signal to be a full bar or (if we must use it as a measurement) a full 100%. This generally conveys that everything is working as expected, and the signal won’t cause any issues with your reception. If you are given a different reading, you should first check the tuning of your television and other equipment. In the end, your main focus should be on the reading for quality, not the reading for strength. This is the only real indicator that the signal might be worth looking into.

There is No Real “Standard” for How Signals Are Read

​You might plug one TV in and find fully-rated signal strength and quality, then plug in another brand to find completely different readings. This has nothing to do with the signal per se, but with the way that different TVs and Set-Top Boxes read and display the signal info. Ultimately, there is no “industry standard” for how televisions do this.

Correctly Reading TV Signal Strength

In order to read your television’s signal strength correctly, you need to know exactly how they are measured. Put simply: a TV signal is a voltage measured in units called dB micro-volts. The scale starts at 0dB, or 1 micro-volt, and continues upward. In most cases, when you have a weak signal, a small adjustment of the dB can really help.

For reference, here is a quick guide to the MINIMUM signal strength levels of several types of televisions.

  • Terrestrial Digital TV – 50dB
  • Analogue TV – 60dB
  • Satellite TV – 52dB

Correctly Reading TV Signal Quality

​With digital television signals, the quality or the “robustness” is often measured by evaluating the signal strength minus the electrical noise that can come from various interfering sources. As these noises are present inside the actual signal, relying on the measurement of the signal’s strength alone will not determine the overall quality. In the end, the more actual signal that can be received by the TV transmitter, the more protection the device will have from noise and interference.

You can measure signal quality in a few different ways:

Signal to Noise Ratio (S/N)

​​This is the measurement of the peak signal reading and the noise floor of the signal, but ignores noise present in the signal itself.

Carrier to Noise Ratio (C/N)

This measures the signal floor and compares it to the signal being received. It doesn’t measure any noise present in the signal, but it does account for it.

Modulation Error Ration (MER)

Considered the best measurement for digital TV signal reliability; this measures both the signal and the noise present inside of it.
Bit Error Ratio (BER)

​There will always be some errors in a digital signal – it’s unavoidable. That is why signals have a built-in error correction known as FEC or Viterbi EC. When you see that 100% reading, you are seeing no errors because correction has already automatically taken place. When there are errors still present after correction, you will see pixelated or blocky images.

The Truth About Amplifiers

Many people assume that the installation of a booster or TV aerial amplifier will increase the signal strength reading on their receiver. Such devices are a good idea if the goal is to overcome signal loss, and they should be installed as close to the aerial as possible (but not within one meter) in order to function well.

If you place the device too close to your television, for instance, you will boost the levels of electrical noise in the signal and introduce new noise to the readings. You also risk overloading the equipment, which is just as bad for the picture as a weak signal.

As a rule of thumb, amplifiers are best used where the signal enters the TV tuner in a weakened state. This should help boost the signal enough to maintain reliable reception.


It’s important to remember – despite all this information – that the signal and quality readings reported by your TV should only serve as a rough guide. As you can see, there is much more that goes into the process, and those who try to make adjustments on their own often do much more harm than good.

When in doubt, contact a professional and have them evaluate your signal, TV, tuner, and / or amplifier with high-quality equipment.

As always, if you have any questions or comments, feel free to send them my way!

Digitec Aerials Preston
​The Watermark, 9 – 15 Ribbleton Ln, Preston PR1 5EZ
Tel: 01772 369629