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The PSK-20  Transceiver

Builders: Click here for troubleshooting support and documentation updates :


Small Wonder Labs is proud to offer the PSK-20  transceiver kit for the exciting PSK31 mode.

There is a 40m kit available, but this one makes no sense for European users because its different tuning range [7.070-074 for 40M]

This design is a derivative of the SSB transceiver appearing in the April 1997 issue of QST. It's been streamlined for ease of construction and alignment, and many of the higher installation-skill components have been designed out. Intended as an entry-level platform for PSK31 use, it covers the 14.0695-14.073 segment of 20M  where most of the PSK31 activity is found. The design retains the same relatively high dynamic range of the QST SSB rig as well as good transmit IMD characteristics.

The rig is crystal-controlled and was designed to work with the popular (and free!) DigiPan software. Output power is 3W PEP. The crystal control provides excellent stability and its simplicity keeps the cost low. Performance characteristics for either 40M or 20M versions are similar.

Kit assembly is straightforward- there are only four toroids to wind. The number of adjustments is kept to the minimum consistent with good performance, and no special test equipment is needed to perform the alignment. There’s no harness wiring- all interface connectors mount on the rear of the circuit board. The board kit includes a 26-page manual with color figures. Step-by-step assembly instructions are included.

PSK-series Interfaces:

  • 12-15V power supply, 1A
  • Antenna jack (BNC)
  • Soundcard Microphone (3.5mm)
  • Soundcard Line/ Speaker Out (3.5 mm)
  • 9-pin serial port (for PTT)

The interface cables to your computer are all ‘off-the-shelf’ items, available from Radio Shack and other suppliers - there’s no soldering of adapter cables required and no extra interface units! Once the transceiver kit is assembled, it's 'plug-and-play'- any operating adjustments are made via your computer.

Computer requirements:

  • Windows 95/ newer
  • Pentium or equiv., 75 Mhz minimum
  • 16-bit Sound card.

The image below shows the full-up 20M prototype of this transceiver in use. 

Click below for a high-resolution (305 kB) image of the board:



The board assembly slides into a standard Lansing Instruments ‘Micropak’ series extrusion enclosure and affixes to the rear panel via the serial-port connector jackscrew hardware.

This enclosure features a handsome black-anodized finish. End panels are included- the image below shows the custom-punched and silkscreened rear panel. 

Complete German or English manual

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