If you have browsed to this page looking for some basic information on getting started with PSK31, or other digital communications, you have found the right page! If you are hoping to add some new life and excitement to your hobby, then you have chosen the right subject. As an introduction to the HF digital modes, or inexpensive upgrade for your digital operations, the information here is a starting point for operating the fastest growing modes of keyboard to keyboard communications.

Here is what you need to get started:

• A Windows95/98 or DOS PC (or Linux) with Sound Blaster compatible sound card installed.
• A "stable" HF SSB ham radio and legal operating privileges (license not required to monitor).
• A digital mode software package for your operating system.
• About $5 worth of Radio Shack or junk drawer parts to make hook-up cables and attenuator pad.
• Approximately 1-3 hours time to put it all together.

Here is what you must do:

• Install the digital mode software package on to your PC. Test your program for compatibility with your sound card by placing the program into the TX mode and listening to hear the digital sound from your PC speakers.
• Read the operating fundamentals found in the Operators Manual and keep a copy handy for reference.
• Assemble, solder and install two cables for audio IN and OUT (or purchase an interface) between the sound card jacks and the radio.
• Use the audio level controls found in most programs to make a one-time adjustment to the Windows sound card Mixer Control program.
• Practice tuning in stations and operating your digital mode program before you answer or call your first CQ.

What else should you know?

• The heart of this method of digital operation is the PC sound card which is being used by the software program as a DSP (Digital Signal Processing) unit. Slower PCs (less than 90 Mhz) may experience sluggish operation with some software packages.
• PSK31 is the most popular of the new DSP modes but will not be the best mode for all band conditions and communication needs. You should try other modes such as MFSK16 and Feld Hell when phase distortion makes PSK31 impractical.
• Most SSB transceivers in use today are stable enough for the narrowest of these digital modes. A transceiver that is known to drift slightly during SSB or CW operation may not be suitable for PSK31, but may be used for Hellschreiber modes.
• Tuning in a PSK31 or MFSK16 signal is the most frequent complaint by new operators to these modes. The precise tones require precise tuning; but this is made easier with point-n-click features and by AFC techniques built into the programs. Tuning becomes second nature after you get familiar with the sight/sound of your program.
  A look at the tuning display on two sound card programs found here. Digital mode sounds are here.
  
• A simple step by step method for wiring and adjusting the sound card set-up is described here.
  
• Other active audio programs that use your PC's sound system may interfere with the sound card program and should be disabled during ham radio operation. It is possible that other audio programs may re-set your sound card mixer settings, causing you to readjust the levels next time you run the program.
• The attenuator pad that you install must provide a simulated MIC input level to the radios MIC circuit. Adjusting the MIC gain will not compensate for an excessive signal level. You must use plenty of attenuation from the sound card output or adjust the sound card output level very low to prevent a distorted signal on the air!
• Software packages to run these modes on your PC are available by searching the Web. There are at least six digital mode sound card programs that are available for PC and one for Linux and Macs. They range from very basic "stand alone" PSK31 only programs to complex programs where PSK31 was an "add-on" feature. The latest generation of sound card software packages contain multiple modes with control features for most ham radio models. Programs like the MixW are user configurable and contain many extra ham radio features.
• Some other modes offered in sound card programs are: Packet (ax25), RTTY, HF Fax, AMTOR broadcast, THROB, Hellschreiber, MFSK16, MT63, Slow Scan TV and Morse Code. ARQ modes like Pactor are not offered in sound card programs presently, but at least one program (MixW) will allow you to use your TNC to operate ARQ as well.
• A source for sound card programs is found here.
• A quick link to freeware programs by IZ8BLY are here.
• A quick link to the MixW multi-mode multi-feature shareware program is found here.

I hope I have convinced you to give it a try! Don't let your lack of typing skills stop you. Typing is just like operating a morse key; the longer you stick to it, the better and faster you become. Have fun and see you on the digi bands...