G3YHV/G0CJG – SARC WSPR TX Mk2

One of the first assembled kits and case constructed by Ken, M0KMI

In early 2021 the next version of the SARC WSPR TX commenced after a quick requirements gathering and a “wish list” from club members.   The hardware has been redeveloped by Colin G3YHV who created the first version of the TX. The software has jointly been developed by Colin and Dave G0CJG.  The software now supports Type 1 and Type 2 message formats and controlled by a user setting.

There are a number of options being considered as there no longer any requirement for custom user specific software to be provided, the original unit required the users callsign/locator to be pre-programmed.  If you are interested in acquiring a PCB + programmed PIC chip please contact us via this link Contact SARC.


Latest News

21/5/21 – Boards available with PIC chip only cost TBD – we need a minimum number of 12 people interested to cover PIC chip postage costs. 

15/5/21 – Documentation updated following observations during first kit builds.

12/5/21- All components and modules arrived, first board built & tested with purchased components successfully. Documentation complete & will be published today.

9/5/21 – PCB’s and components arrived,  final missing part – DDS module due this week.

9/4/21 – G0CJG/M0KMI working on modifications to the N7DDC auto tuner for QRP input

16/4/21 – Most of the components have now arrived other than the modules coming from the far east!

4/4/21 – Design and testing is now complete and components on order. 


Build Documentation – SARC WSPR TX Construction v1.3

 

SARC WSPR TX v2

SARC WSPR TX v2

 

Detailed below are the features of the Mk2 version of the project and differences from the original TX.

  • PCB – move to commercial production
  • Display – upgrade from 16×2 character display to monochrome OLED SSD1306 i2c module
  • Time – replaced UBLOX GPS module with DS3231 real-time clock battery backed module
  • DDS – AD9850 retained due to frequency range
  • PA – upgrade from single transistor to new PA design
  • Power Output – 3 power settings up to 100mW 
  • PIC Chip – 18F1320 8k + 8Mhz oscillator to 18F26K22 64k + 64Mhz oscillator
  • Bands – 80-10 including WARC bands
  • Software – major change from a user pre-programmed configuration to user defined Setup and User menus where all key parameters can be changed/set
    • Callsign
    • Locator
    • Clock (need only be set once unless battery replaced)
    • Single/3 band hopping
    • Output Power 0-23dBm
    • Tune up mode (TX for 45 seconds)
    • Set TX % on time
    • Set Band
    • Set Screenmode (invert display and change brightness)
    • Calibrate DDS
    • Calibrate TX Drive levels
    • Reset NVRAM settings

 

WSPR TX2 - M0KMI

WSPR TX2 - M0KMIWSPR TX2 - M0KMI