Digital TV receivers, or digital converter boxes, are stand-alone components that allow analog televisions to receive digital signals. As of 12 June 2009, most television signals in the United States stopped broadcasting on an analog signal and are now broadcast in digital only. Analog televisions without digital capability would not be able to receive a digital signal and would therefore be rendered unusable without a digital TV receiver.
Digital TV receivers convert digital signals into an analog signal, allowing an analog television to continue to receive digital television broadcasts. Digital converter boxes can be purchased at most home electronics retailers and are relatively easy to install and use. An antenna is connected to the converter box and the box is connected to the television. Depending on the converter box and TV, certain television functions, such as changing the channel, may need to be performed through the converter box itself and not through the television directly.
Consumers who subscribe to a cable or satellite television service do not need external digital TV receivers, as their cable or satellite service already allows their TVs to receive a digital signal. Only those users who received free “over the air” analog television signals, through the use of an antenna, need a digital TV receiver. After 1 March 2007, all televisions sold in the United States are required to have a built in digital receiver. Owners of these television sets should be able to receive digital broadcasts without the use of external digital TV receivers.
It’s important to note that a high-definition television (HDTV) is not necessary to receive over the air digital TV signals. High definition television is a form of digital TV broadcast that offers greater picture clarity and sound and requires an HDTV to receive the high-definition signal. Many consumers find the superior quality of HDTV worth the additional expense; however any analog television with a digital TV receiver will be able to receive regular digital TV signals, whether it is a high-definition television set or not.
The United States Congress mandated the switch to an all digital television broadcast standard for two main reasons. The first is that digital broadcasts are of a higher quality than analog broadcasts and is a more effective means of transmitting information. Broadcasters are able to transmit more information, simultaneously, with digital signals than they are able to with analog signals. In addition, freeing up the analog airwaves allows the frequencies formerly used by broadcasters to be used for other purposes by public service providers and for wireless telecommunications.