Making a DIY TV can be a reasonably easy process and involves using an existing television set. Measure a regular television screen, mark it out on a piece of material like cardboard or wood, and cut the measured part out. Measure the length and height of the screen to create the focusing board before using a Fresnel lens to measure a circle in the board. Make a small box which will later fit inside the main box before painting all the materials. Assemble with duct tape before attaching the board and Fresnel lens to the smaller box, and then install all of this inside the large box.
To create a do it yourself (DIY) TV, measure an existing television screen. Use a pencil to mark out these measurements on a large piece of cardboard or wood. There will be four pieces in total with a depth of 18 inches (45 cm).
With a sharp instrument like a Stanley knife, cut the cardboard or wood. Place these pieces to the side and concentrate on the focusing board. The height and length of the screen is the size of the focusing board. Use a pencil to draw lines from one corner of the board to another to create an "X."
The outline for the DIY TV is starting to take shape, so place a Fresnel lens in the board’s center. There are a variety of circles in the Fresnel lens; choose the fifth largest one and trace it onto the board. Use the sharp instrument to cut out this circle. When cardboard is being used, the circle needs to be cut at a slight angle. The reason for this is to make sure the back of the hole is larger than the front.
Create a smaller box to fit inside the larger box. The depth of the smaller box will be 9 inches (22.5 cm). Cut the smaller box in a way that makes sure the height and width are also slightly less than the larger box.
Paint the inside of the wood or cardboard black for a better picture. The outside color is a matter of choice. It can also be painted black, a different color, or be left alone. Use matte black paint because dark paint equals a better picture.
Do not place the DIY TV pieces together until they are all completely dry. Stick the edges of the boxed together with duct tape and assemble both boxes. The sides can be strengthened with more duct tape. It is also important to ensure the edges of the box are completely closed.
Place the Fresnel lens into the hole in the focusing board. Attach this board to the small box. At this stage, the normal television must be upside down. Use duct tape to attach the outside box to the television. A completely sealed box means no light will escape.
Place the small box inside the large one. This completes the DIY TV project. It is now possible to watch programs on a projection TV screen. To focus, push the DIY TV towards the wall, and then pull it back until the correct screen size is reached. The smaller box will focus the picture.