Software defined radio has taken hold with the scanner enthusiasts but with limited technology available for use at HF frequencies the options for shortwave SDR have been few but now all that has changed.
For decades radio operators have used converters on their existing radios to allow the reception of parts of the radio spectrum other than those the radio was designed for and avoiding buying whole new radio systems.
Entry level SDR comes in the form of very small receivers originally produced for the digital television market that plug into a computers USB port giving a simple and fast connection for transferring data.
Because USB receivers only start to receive well above 30 MHz it makes them no good for listening to shortwave radio. Adding a separate up-converter that will pickup shortwave signals then retransmit then at frequencies that a USB receiver can handle gives us a pathway into using the power of SDR on the entire shortwave bands.
The up-converter itself comes fully assembled in circuit board form with all connectors in place to wire into the computer and USB receiver. If you already have an existing shortwave antenna system it is unlikely to have the small SMA connectors that are needed to plug into the up-converter and if you are not prepared to change the connector there is always the option of buying or making an adapter.
Even though there are two pieces of equipment used to make a SDR shortwave radio it does have its advantages. The main workhorse of this setup is the USB receiver which does the job of serving the SDR data to your computer and as thing progress with better technology you need only to upgrade this to enjoy a better front end performance.
Why Use Shortwave SDR?
The ability to process huge chunks of the radio spectrum makes SDR a great tool for the shortwave listener especially if you regularly work with the many data modes transmitted on the HF bands. Storage of media and voice is only limited by the capacity of your computer or by moving archived material over to more permanent storage (DVD, CD or Flash drives).
There are no mode dependent electronics to restrict what signals you listen to as all the processing is done on a computer instead of the receiver, this does go some way to future proofing the kit you buy now as there is only an easy to change software interface limiting the types of transmissions received.
Much of the SDR software available online is open source meaning that improvements and tweaks are always being made by both the amateur and professional sides of the software defined radio world.
The shortwave SDR equipment itself is easy enough to understand and the only thing required is a little aptitude with computers to get to grips with the SDR radio interface programs you will be using to extract all those lovely signals. If you have no experience with this type of product we would suggest doing a bit of research before hand to see if SDR is the right fit for you.