Radiosophy's HD Radio

A New HD Radio

You would think that under the category of tabletop clock radios, there wouldn’t be much to attract a Tom’s Hardware Guide reader. Think again, with the Radiosophy HD100, a stylish device that delivers digital HD radio at a very reasonable $99 price.

Why a clock radio? Several reasons: they are portable and can fit in any room, including those that don’t have a convenient cable connection for abundant cable radio channels. You don’t have to pay anything for their programming unlike satellite TV or cable, and there are now many choices of devices that offer better sound quality for not a lot of cash.

The HD100 unit is large for standard clock radios but it comes with a bunch of features, including an auxiliary input that can handle MP3 and iPod connections so you can play your music over its built-in stereo speakers. (It lacks a connecting male/male 1/8" cable, though.) It comes with a small external antenna, and the LCD display is big enough for those of us of a certain age to be able to see the time display without our glasses. Speaking of the display, you can also view information about song title and artist while the song is playing.

HD doesn’t stand for high definition, by the way, but for a scheme that is a hybrid of digital signals using the same FM and AM frequencies that we all know and love. The neat trick with HD radio is called multicast. This means that a single radio station can broadcast multiple signals and programs over one frequency: you can have rock, talk and jazz "stations" all coming from a station that previously only had one program format. And all of this programming supposedly comes at near CD-quality sound with no static. There are also purportedly more than 1,000 stations that offer HD programming right now: in my area in St. Louis I found more than a dozen when just scanning the FM band. They came in clearly and without any problems once I attached the external antenna.

Because HD stations use both analog and digital signals, there is a bit of transition as you scan through the dial to find a station playing something you want to hear. The radio uses the analog signal to seek the station, and then once it "locks onto" the signal, it will switch to the digital HD program if it is available. At that point, you may lose a few seconds of programming or the radio may go silent for a few seconds, The vendor says this is an artifact of how the stations are broadcasting their programming, since the two signals aren’t always simulcast.

Summary

HD radio isn’t for people that live in rural areas that are far from the broadcasting towers of most stations; this is because like a digital cell signal, you either will have reception or it will go dark on you completely. Also, AM stations were initially not allowed to broadcast HD signals at night because their analog signals can travel great distances then and the HD signals could interfere with each other, but this restriction was lifted this month.