PSK 31 is a popular digital mode used for transmitting and receiving text via radio.
My friend, Jeremy Widner, K0PDX has become very effective and successful with the digital modes, particularly PSK31. Copied here is a presentation he has offered on the topic.

You can also download this presentation as a Power Point presentation by clicking here.

Check out Jeremy's outstanding web site at:



What is PSK31?

  • A digital mode created by Peter Martinez, G3PLX

    PSK stands for Phase Shift Keying

    31 is the bit rate



Characteristics of PSK31

The power in a PSK-31 signal is concentrated in a 31 Hz bandwidth, versus 250 Hz for RTTY and 3300 Hz for SSB

Transcontinental QSO’s using PSK-31 are possible using less than 50 W under any conditions and when conditions are good, QRP (Less Than 5 Watts) PSK-31 contacts are possible to any point on the planet.




Amateur transceiver that has low frequency drift

    • Any modern solid state rig is OK

    • IC-706
      Omni VI

Personal Computer

  • Most PSK-31 software is compatible with any version of Windows
    Sound card (16 bit Sound Blaster or better) is required

An interface that connects the PC and the transceiver

  • Commercially made (RigBlaster, RASCAL, etc.)
    Audio Coupled

Computer Software

  • Ham Radio Deluxe (HRD)


K0PDX Shack

  • IC-718
    Interface cables purchased from Associated Radio
    eMachine running Windows 7
    Ham Radio Deluxe


PC Interface

  • The interface provides matching and isolation between the audio inputs and outputs of the PC and the transceiver

    The interface may also provide connections between the computer’s serial port and the PTT input of the transceiver

    Commercially made interfaces provide lots of functions and are very easy to install. However, they can be expensive.

    A simple homebrew interface can normally be built for less than $10.00.

    Certain transceivers can be connected directly to a PC:
    • - ICOM 756
      - Yaessu FT-920



Acoustic Coupling

Rig’s speaker is placed near the PC’s microphone

Rig’s microphone is placed next to the PC’s speaker

VOX is used for T/R switching

Absolutely no extra equipment required.
Good electrical isolation between PC and rig
  • Transmit levels can be tricky to adjust
    Ambient noise degrades signal



Basic PSK31 Setup

  • The HF rig should be in the USB mode.

    Output power should be set to 30 – 50 (this is a full duty mode – do not set to full power)

    The transmit level should be set using the level controls in the software or the rig’s mic gain control so that the ALC level is just tickled

    The receive level should be adjusted to a level that does not overdrive the sound card

    PSK31 software running


PSK31 Software

  • There is several good free software packages available:
    • - Ham Radio Deluxe
      - Hamscope
      - Digipan


The Waterfall





HRD QSO Screen



HRD Super Browser Screen



Where to find PSK31

PSK-31 activity is concentrated around the following frequencies:

1.83815 MHz
3.580 MHz
7.035 MHz
14.07 MHz
18.100 MHz – Great Band for Europe and thePacific
21.070 MHz
24.920 MHz
28.120 MHz



The Success of K0PDX

  • Over 680 contacts on PSK31

    75 countries

    All HF bands except 160 meters


K0PDX PSK31 Contacts,
December 2009 - February 2010



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