Police scanners have become popular accessories for people interested in following police activity in their neighbourhood. You can build your own antenna for a VHF/UHF scanner using very basic materials and with a minimum of work that will work just as well as any store-bought model.
Before You Begin
A coaxial cable makes the most important ingredient for your antenna. You will need enough cable to run from the antenna up on the roof down into your house; most TV-type coaxial cables will work. Run your antenna inside if you like, using less cable, but keep in mind that this will affect performance. You will also need three pieces of #12 or #14 wire measuring about 20 inches each, a soldering gun or iron, solder, sealer and a sharp knife for cutting off the coaxial cable insulation.
Remove the outer insulation and the metal shield from the outside of the first 20 to 21 inches of the coaxial cable, leaving the inner wire and its insulation intact. Leave about 3 inches of the metal shield exposed before the outer insulation starts again which will allow you to solder the other wires to it.
Next, solder the three radial wires to this section of shield. Remember not to solder them to the inner wire.
Make a small loop at the end of the coaxial cable, and hang the antenna from any nonconductive rope, cord or heavy string. Keep the three radial wires at least four 4 away from any metal surface. You can also tie them at the ends to any nonconductive surface, allowing them to reach down at a roughly 45 degree angle.