PSK31

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: http://k0pdx.us

 

What is PSK31?

• A digital mode created by Peter Martinez, G3PLX
  
  PSK stands for Phase Shift Keying
  
  31 is the bit rate
  
  

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.

• Any modern solid state rig is OK


IC-706
IC-746
TS-940
TS2000
FT-1000
Omni VI

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

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

• Ham Radio Deluxe (HRD)
  Digipan
  Hamscope
  

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

• 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
    

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

Advantages

Absolutely no extra equipment required.
Good electrical isolation between PC and rig

Disadvantages

• Transmit levels can be tricky to adjust
  Ambient noise degrades signal
  
  

• 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
  

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

Receive

Transmit

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

• Over 680 contacts on PSK31
  
  75 countries
  
  All HF bands except 160 meters