The idea of using computers to make receiving international radio signals easier has been around since the 1970s. It was only in the ‘90s when governments and military forces began using the technology in force, and only in the last few years that the technology has become available and affordable for the general population.
Software-defined radios, or SDRs, combine the utility of analog shortwave radio and the precision of modern computing. An analog radio receiver can be teamed with a computer via a sound card and analog-to-digital coupler to make international radio signals — which are sometimes plagued with noise, interference and static — cleaner and easier to hear.
Shortwave radio is an efficient way to get radio signals from around the world. It’s relatively cheap and AM radio travels long distances very well as a shortwave signal. It’s used a great deal on the high seas, transmitting weather signals and directional beacons, along with encoded information in various formats. It’s also used in poorer and remote countries as a cheap and easy way to spread news and information to citizens.
AM signals, however, also tend to degrade when sent over very long distances, making them hard to hear or decode when received. A digital system, which can be used to lock on and clean up a signal, will help make shortwave signals easier to hear.
In the hobby of shortwave listening (SWL), it’s often challenging to listen to shortwave signals over long distances. This part of the hobby is called DXing. Because shortwave signals are analog, it becomes difficult to listen to weak signals because of atmospheric conditions and distance. SDR software helps make these stations easier to listen to using digital filters, noise dampeners and signal detectors.
SWL can be an expensive hobby.
The higher-end radios alone can cost several thousand dollars, and analog technology for filters and antennas several hundred dollars more each. Putting up an antenna can take up a lot of space as well, with only people owning property able to mount them.
Some of the software for SDRs is open source and free to download and the technology helps cut down the cost of this interesting hobby and make it more accessible to everyone.
Experiencing media from a far-off country, meant for those who live in that country, can offer valuable insights into how that place thinks and feels. The experience is even more satisfying than social media, since radio from the region is unfiltered. Understanding how we feel about each other through international radio makes the world smaller, and easier to understand.
Steve Marlow is the program co-ordinator at CFBX, an independent radio station in Kamloops. Tune in at 92.5 FM on the dial or go online to thex.ca.