moderately fast, have
some USB ports, and a
sound card. The input data
to the computer is entirely
in digital form, coming
from the TV tuner via
USB. After applying digital
algorithms for filtering and
demodulation in the PC,
the processed digital data
is presented to the sound
card — all in the digital
domain. Finally, the sound
card is used to convert the digital data to audio to drive
speakers or headphones. Before we continue with details
of the design, let’s take a closer look at the little tuner
device that makes this project possible.
Mini DVB-T USB Tuner
The digital terrestrial TV age is in full bloom for
millions of viewers around the world — especially in
Europe. Analog terrestrial TV has been replaced by the
new Digital Video Broadcasting Terrestrial (DVB-T)
standard in many places. Viewers use mobile USB TV
tuners with their computers for reception of HDTV
broadcasts. Mobile tuners have compact dimensions —
about the size of a memory stick. They plug into and are
powered by the USB 2.0 port of your computer.
Figure 2 is a photo of a DVB-T tuner package
purchased on eBay for about $11 (including shipping). As
you can see, a remote control and an antenna are
included — ideal for watching TV on your laptop.
We will not be using the DVB-T tuner for TV viewing
in this project. Besides, it would not work in the US since
the DVB-T standard is not implemented here. Instead, it
will be repurposed to act as a wide-band tunable SDR
receiver. Hence, we will not need the other items in the
It was the simplest of times — it was the most complex of times. Indeed,
much like those words, this shortwave radio project is probably the simplest,
most complex one you have ever seen. It is simple because the main
hardware components are low cost, readily available, and easy to assemble.
It is complex because you need to download and install a special USB driver
and other software on your PC — and get it all working together. Once the
components are assembled and the software is installed, however, you will
have a very versatile shortwave radio that covers the 1-30 MHz range, and
provides many enjoyable hours of shortwave listening and experimentation.
Since the software is free and the components are cheap, you should be able
to build this receiver for around $25.
July 2015 41
FIGURE 2. Low cost DVB-T package.
FIGURE 1. Block diagram of SDR SW receiver.