PSK-31 Digital Radio Signals Work The World With Low Power Radio

Did you know there is a digital radio mode that lets you talk around with world using low power transmitters and which does not require you to know and use Morse code?

It is called PSK-31, though it is often abbreviated to just 'PSK', and it allows any radio operator who is licensed to use the HF bands (the shortwave radio bands) to send and receive digitized PSK radio signals.

All it takes is a simple interface between your two-way radio transceiver and a personal computer, plus a software program to do the translation for you. The whole connection process is far simpler nowadays, since we can now use the sound cards that are an integral part of all personal computers,

There are several PSK-31 programs available that can be downloaded over the internet and used to receive and send PSK31 signals. Some digital radio programs have several different digital modes built-in, and a couple of them can even control your radio transceiver completely from your PC as well.

A few of the PSK-31 radio programs are free, while others cost a modest amount of money.

Some of these digital radio software programs can handle PSK31 only. Some handle other digital modes designed to work on the VHF or UHF bands, where PSK31 was not designed to work.

Some radio programs combine PSK software with other features such as ham radio logging programs that makes a written record of every radio station you have communicated with, plus the radio frequency, the date and time, a signal report and the name and location of the radio ham you have communicated with.

Most PSK-31 transmissions are made on the Amateur Radio 20-meter band, an HF band which starts at 14.000 MHz and runs almost to 14.350 MHz. The 20m Ham band is divided into sections for different modes, so where you may transmit in that band depends on your license and what country you are in. It also depends on your mode of transmission, be it CW, AM, SSB and so on.

Most PSK-31 signals will be heard on around 14.070 MHz, and remember to set your receiver to USB or upper side band. (The use of USB mode for PSK extends to the bands below 10 MHz as well.) Other HF PSK31 frequencies center on: 1.838 MHz (160m), 3.580 MHz (80m), 7.035 MHz (Europe 40m PSK) and 7.075 MHz (USA 40m PSK), 10.140 MHz (30m), 14.070 MHz (20m), 18.100 MHz (17m), 21.080 MHz (15m), 28.120 MHz (10m).

You will need to do a little bit of investigation before you choose what to get. And like most hams, you will probably end up owning several different programs to do the job.

Because PSK-31 is a digital mode of radio transmission, you do not need high power. Most knowledgeable radio operators use 10 Watts of power or less, and many use 5 watts, 2 watts or one watt of power - true QRP (low power) transmitter outputs. If you are silly enough to transmit PSK at higher powers, your signal will splatter over other amateurs' signals and you may get reported to the authorities.

(On a sidenote, Amateurs are very good at hunting hidden transmitters, they do it for sport at many Amateur Radio club meetings and outside events such as Field Days.)

Sound Card Interfaces

Apart from getting the software to do PSK31, you will need to purchase or build a simple sound card interface that connects your two-way radio with a personal computer so you can receive and send messages to/from other radio amateurs on the HF (high frequency) or shortwave radio bands.

See below for a list of links to Digital Radio/Sound Card interfaces and kits: 

This list below is by no means complete, but it is a good start. To find further information, just do a Google search for 'radio PSK sound card interface' on your computer and see what else you can find.