This is because your television aerial is being moved which will cause your channels to become distorted. The aerial is essential because they enable you to receive the correct channels.
There are many different types of aerials which have many differences. Take a look at the aerial descriptions and what each aerial is for.
The most used aerial is the Yagi aerial which is attached to a tall pole that is fixed to the roof of your house. The Yagi aerial has prongs on the side which are also known as aerials. The more elements the aerial has the better it picks up signal which is why they are so popular. These aerials are used to transmit analogue television. Which is why they used to be popular in the past before the digital switch-over.
Grid aerials are another aerial which has shown to improve television reception in areas which have little reception. These aerials are also called high gain aerials but do not usually provide Freeview reception.
You could alternatively use an indoor aerial but do not usually pick up much signal. These are only useful in areas which do not have thick walls. Not many households use indoor aerials for their television signals.
Another type of aerial which is used for people who live in poor reception is a Digital High Gain aerial. These aerials have more than one reflector which usually have 100 elements, so that it picks up more reception. Digital high gain aerials are slightly more expensive than Yagi aerials but are perfect for people who want to watch television but would not be able to view the channels without this type of aerial. High Wycombe aerial installation can install this type of aerial.
There are other alternatives to having these aerials such as a satellite which you could choose to have installed from a number of companies which means you will then have access to many channels.