Digital Televisions

January 23, 2024
Tomasa Lopez and daughter

Digital v Analog SignalsSince June 13, 2009 all full power television broadcasters have been beaming their programming via a digital format. That format, which replaced the analog NTSC signal, is called ATSC. ATSC is an acronym for Advanced Television Systems Committee. Learn more about the ATSC at All televisions sold in recent years incorporate an ATSC digital tuner. A second digital format, QAM, is the standard for cable television.

QAM is an acronym for quadrature amplitude modulation. QAM is a modulation scheme, just like AM (Amplitude Modulation) and FM (Frequency Modulation), that can be used for digital signals. The Capitol Connection offers a set top box that receives both ATSC and QAM signals, allowing older analog televisions to receive both new digital services. All new TVs have an internal ATSC tuner and many have a QAM tuner too. With an ATSC and QAM tuner the TV is ready to receive all digital signals, broadcast and cable, and in the case of the Capitol Connection, the TV would not need a set top box.

One of the reasons the United States switched from an analog signal to a digital one is that a digital signal makes more efficient use of the bandwidth allotted to broadcasters. Broadcasters can now offer more than one channel using the same amount of bandwidth allotted in the past. For instance, WETA, the local public broadcasting affiliate in Washington, DC offers their regular programming on channel 26. They have a second channel for HD programming, a third, called “How-to” and a fourth with educational children’s programming. The channels are 26.1, 26.2, 26.3 and 26.4.

Digital TVAnother reason for the digital switch was to make room in the TV band for first responders, police and fire and rescue squads, while freeing up additional spectrum for mobile wireless broadband services. The ever growing demand for new wireless services and devices has placed increased demand on the finite resource comprising the usable portion of the electromagnetic spectrum.

When purchasing a new TV, make sure it includes a QAM tuner. It’s always best to check the manufacturer’s specifications. Don’t rely on the young salesperson at that big box store. As a final check, look at the box and make sure it lists both ATSC and QAM tuners. One manufacturer changed the specs on the product without changing the model number. It’s always best to keep up to date when purchasing a new TV to make sure you have the latest information.

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