WSPR TX Mk1 Prototype


by Colin Chidgey

The club was looking for a construction project for 2017 ideally for everyone to build either at the club or with assistance that would be of general interest and supplied in the form of a kit suitable for novice builders. There are no surface mount components so soldering should not be problem.  Two projects came to the top of the list and the first was the WSPR Transmitter.  

This project has been superseded now please see WSPR TX Mk2

The kit enabled you to construct a WSPR Transmitter capable of running a maximum of 20mW on all bands from 1.8 – 14Mhz on the specified WSPR frequencies.  The software is provided on a PIC chip which has been be pre-programmed using Proton BASIC with the users callsign and locator. This is a restriction as the BASIC compiler is a licensed product and only 1 club member has the software.  The actual code will be published but the club will not provide programming services to non-club members. All the components others than a case, the chassis mount components and power supply are supplied.  Construction should only take a few hours with the most effort to build the kit into a case. 

The kit uses several pre-built modules which can easily be acquired for a nominal price from eBay.

These are NEO GPS module for accurate timing which are commonly used with drones.

GPS Modules

DDS AD9850 module to generate the required frequencies.

DDS Module

The display is also a module consisting of the LCD 1602 (16 characters x 2 lines). 

WSPR TX Mk1 Display
40×2 Line Display Module

A finished project from one member.