Computers have revolutionized the ham radio hobby. Before home computers became commonplace, amateur radio was largely analog. Users manually tuned up and down the radio spectrum to search for signals, and used paper and pencils to copy messages and take notes. Today, nearly every aspect of the hobby can be done on a computer. Even if you do not yet have an amateur radio call sign, you can use software such as Hamsphere to get started and begin talking to other people around the world. After you progress in the hobby and obtain your own radio, you can use more powerful software including EchoLink and JRX to control your equipment from a computer and gain more enjoyment.
Hamsphere (link in Resources) is software that uses your computer or mobile device to simulate the ham radio experience. While a traditional amateur radio sends signals over radio waves, Hamsphere uses the Internet. This means that you can talk to people virtually anywhere in the world, even if you do not have a radio, official call sign, or antenna equipment.
The Hamsphere program uses a "virtual ionosphere" to replicate the atmospheric conditions often encountered by ham operators in the real world. This means that your voice reflects or "propagates" around the world based on weather conditions and other factors. You can fine-tune the settings of the Hamsphere radio and select a variety of simulated antennas on nine different bands, just like a real radio. This allows you to experiment with how radio signals work, without the need to invest in expensive equipment and large antennas.
Hamsphere is available for Windows, Mac, and Linux computers. You can also load the app onto an Android or Apple mobile device. The full version of the software costs around $40 per year, while a free trial is also available.
EchoLink (link in Resources ) combines computers and ham radio transceivers to create radio networks. While some programs, such as Hamsphere, simulate only the amateur radio experience, EchoLink connects computers to actual radios in the real world. This program essentially creates virtual radio repeaters using the Internet.
Traditionally, ham radio operators can communicate only with other users who are within range of a radio signal. EchoLink links radios over the Internet, and greatly expands their usable range. For example, a user in Michigan can use EchoLink to connect her computer and radio transceiver to another user in Florida. Ham radio enthusiasts can then talk to people in the other state, even though they are a thousand miles away.
EchoLink is available only for Windows computers. It is free to download and use, however you must have a valid FCC amateur radio call sign to fully use the program.
Like EchoLink, JRX is intended to be connected to an actual ham radio by licensed operators. However, JRX does not create long-distance radio links. Instead, you can use the program to control a radio directly from your computer screen. This software essentially acts as a powerful "remote control" that is compatible with over 200 radio models.
One of the most useful features of JRX is the spectrum scope display. This gives you a visual representation of radio waves, so that you can quickly find and tune in to interesting signals. You can also scan up or down to detect active frequencies. Once you find interesting activity, you can save a list of favorites for later use. JRX is available for Windows and Linux computers, and is free.
HPSDR stands for "High Performance Software Defined Radio," and is a completely open-source program. HPSDR is fairly advanced software that allows computers to decode amateur radio signals in real time. This usually requires dedicated radio hardware; however, HPSDR uses the computer processor for the task. The program is primarily designed for expert users who enjoy experimenting with cutting-edge technology.
You can download various HPSDR modules and build a custom radio that runs completely within the software. For instance, if you want to listen only to incoming transmissions, you might install and use only the HPSDR receiver and filter modules. If you later want to transmit as well, you can add this module and upgrade your computer-powered radio without adding any actual hardware. HPSDR is available for Windows, Linux, and Mac, and is free to use for non-commercial purposes.