You must have seen a long thin rod-like structure coming out of all your devices that work on radioactive frequencies. This thin rod is not set there to create a radio look; rather, it has a very special purpose. It is known as a screwdriver antenna, and it functions to tune the radio. It is not only used in the radios, but you might have seen it in ham operators and other devices too.
The long screwdriver antenna has two ends. One is the upper end which is known as a whip antenna, and the other one is the cylindrical housing at the lower end. The lower end of the antenna is a bit thicker than its top. Both of these antennas have their particular functions. A screwdriver antenna is usually made up of aluminum and does not require any external antenna tuner.
The working of the screwdriver antenna is based on its installment. If you install it properly, then it will work perfectly. If you have installed it on a plane surface, then it will give you good results. The first-ever design of screwdriver antenna was given by Don Johnson, who leads to its invention. The design included an antenna like a vertical rod with an adjustable center. A remote was used to adjust the center of the screwdriver antenna.
The screwdriver antenna catches all the signals from outside. A reversible DC motor is present inside, and it is operated with the help of a remote and a DPDT switch. When the frequencies of the signals are not matching, you need to change them to tune them at a particular station. You can easily change the frequencies with the help of screwdriver antennas. The extension of antenna loaded coil functions in catching the signals and setting the desired frequency. The band coverage of a real screwdriver antenna is from ten to seventy meters.
We can say that the screwdriver antenna is a whip suspended in a tube that is housing a motor that is used to adjust the tuning coils of the antenna. Working as the motor, the screwdriver antenna also has different characteristics for performing different functions. These functions mainly include catching the signals transmitting to the DC motor to generate required frequencies. You can also make the screwdriver antenna on your own. All that you have to do is adjust the antenna’s frequency and wavelength according to their need. If the wavelength is more, the length of the antenna will be longer, and vice versa.
Besides radios, many other accessories such as switches, remote controllers, weather covers, mounting brackets, and various covers are included in the screwdriver antenna. The most common use of screwdriver antenna is in walkie-talkies and satellite phones, where a particular frequency is used to transmit the signals. This antenna can also be used in all types of vehicles that use radio to tune the frequencies. The car GPS also works with the help of a screwdriver antenna attached to the car.