What is HD Radio broadcasting?
HD Radio technology provides a method for radio stations to distribute their program material digitally. The quality of digital signals is higher, and the digital form allows stations to broadcast additional information as well, such as program information, traffic conditions, and emergency alerts.

What's the difference between satellite radio and HD Radio technology?
Satellite radio is a subscription service that requires users to pay monthly fees for content delivered to them from networks of satellites. HD Radio broadcasting is commonly referred to as "terrestrial digital radio" because it operates compatibly with the same frequencies AM and FM stations are on currently. And, while you'll need a new receiver to get the new digital content, once you get that the service is free.

How do I listen to HD Radio broadcasting?
Listening to HD Radio programming requires two things - a station that has converted its signal to HD Radio technology (like WKNO), and a receiver that picks up the digital signal.

What programs can I hear on WKNO-HD?
WKNO-2 in HD at 91.1-2 features programs like Talk of the Nation and Fresh Air; plus new shows including Tell Me More, featuring NPR"s Michel Martin; Day to Day hosted by Alex Chadwick and Madeleine Brand; and This American Life hosted by Ira Glass.  WKNO3 in HD at 91.1-3 serves the dedicated public radio news listener with around-the-clock BBC news coverage.

How does it work?
1. Basically, digital radio works the same as conventional radio. There’s a signal on one end and a receiver on the other. But there are a few key differences.

2. Instead of sending out one analog signal, stations send out a bundled signal – both analog and digital. Because it is digital, textual data such as traffic, stock info and song titles can be sent out, as well. 

3. The digital signal layer is compressed. 

4. The combined analog and digital signals are transmitted. Inevitably, radio signals bounce off objects, causing what is called multipath distortions. This is what causes the static in conventional radio receivers. HD Digital radio receivers are designed to sort through reflected signals, reducing static, hiss, pops and fades. 

5. Finally, the signals reach their destination. Both broadcasts are free, with no subscription fee. To hear the digital broadcast, all you need is an HD Radio receiver.

To learn more about HD Radio, please visit www.hd-radio.com.  And when you're ready to make that HD Radio purchase, check out the NPR shop.