WSPR Documentation and Files

This page contains links to the documentation and software for both WWoT and Versatile WSPR transmitters. The hardware and software work with Raspberry Pi (Pi) 2, 3 and 4. Be sure to download the correct software for the model Raspberry Pi (Pi) you’re using (2,3 vs 4).

WSPR Without Tears (WWoT) is an approach to getting an actual WSPR transmitter up and running so you can enjoy working with WSPR and avoid dealing with the headaches associated with building a working system. What makes it really interesting is that WSPR is optimized for operation at very low power. The WWoT board puts out a whopping 100mW-200 mW which is capable of reaching impressive distances even with a bad antenna.

The WWoT board is an inexpensive way of turning a Raspberry Pi (Pi) single-board computer into a WSPR transmitter.

TAPR offers two versions of a WSPR “hat” to use with Raspberry Pi single-board computers:

  1. 20m, 30m, 40m fully assembled and tested (soon to be obsoleted by ‘VW’ versions…)
  2. 160m, 80m, 15m/17m, 10m/12m partial kit – user has to solder low pass filter and drain inductor (160m, 80m) (supplied)

We use a Raspberry Pi computer to generate WSPR transmissions. Our board plugs into the Pi and amplifies and filters the output (the Pi output is a very low power square wave that would be illegal to transmit due to its harmonic content). The Pi generates the WSPR signal in software and utilizes timing data from the Internet to calibrate its internal clock and transmit frequency, so you don’t have to do it. Setup is done through a web browser (e.g. Internet Explorer, Firefox, Google Chrome …). No programming required.

NOTE: The Versatile WSPR VW) transmitter is a kit. The low pass filter components have not been installed on the VW board. This allows us to use a common circuit board for multiple bands. You’re getting a circuit board and a bag of 7 components (3 inductors, 4 capacitors) that constitute the low pass filter. These are through hole parts that have to be soldered to the circuit board (we wouldn’t make you solder surface mount parts). Frequency/band is software-settable.

NOTE: The WSPR transmitters do not include the Raspberry Pi, power supply, microSD card or antenna.

Link back to order page

WSPR Documentation

WSPR Readme

WSPR WWoT User’s Guide 

VW WSPR User’s Guide

VW WSPR Bias Adjustment

WSPR Troubleshooting

WSPR Files

WSPR SD Card Image for Pi 2, 3

WSPR SD Card Image for Pi 4

Win32DiskImager Download

TAPR WSPR Executables

Alternate WSPR Installation Procedure

Lee Bussy (AA0NT) has been very giving of his time, skill and efforts. He created an installation script that is much simpler and faster than what we currently have. The only catch is that you have to be able to log onto your Raspberry Pi and issue commands from the command line (either with keyboard and monitor or via SSH).

Type (copy/paste) the following line into your Pi at the command line prompt to invoke the script. You’ll be asked a few yes/no questions. The script will update and install the necessary software onto your Pi.

curl -L | sudo bash

After the installation completes you enter your parameters by typing the following into a browser on your PC/MAC/Linux box:


where you substitute the actual hostname of your Pi for hostname above. For example, if your Pi’s hostname is billy, then you would type:


Alternate procedure if you have trouble with the hostname, you can substitute the Pi’s IPaddress for hostname. For example, if the IPaddress of your pi is (enter ifconfig at the command line of the Pi to get this) you can type the following into your browser:

***Note: Use http instead of https. ***

Again, many thanks to Lee for an excellent addition to the WSPR project.