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WSPR-TX Mini Transmitter  (Needs components, read text)

WSPR-TX Mini Transmitter (Needs components, read text)

SKU: 1017

The WSPR-TX Mini is a standalone all band WSPR transmitter with built in GPS  and GPS antenna for the radio amateur experimenter.


Some quick features:

  1. Standalone operation, PC required for configuration but not for operation.
  2. Works on any Ham band from 136kHz to 70MHz
  3. Is powered from 5V or a single LiPo
  4. Can be expanded with product #1023 1S LiPo Charger 600mA for battery power.
  5. Is designed with battery operation in mind as is using several power saving techniques to conserve power and operate for extended periods of time from a single LiPo battery.
  6. Pre-built and tested except for a output low-pass filter that needs to be built by the user.
  7. Comes with on-board GPS module and GPS antenna.
  8. Set up your call-sign and apply power and off you go!
  9. Open source software and Schematic is published on Github.


Timing and Maidenhead position is automatic from the GPS network.

Take it camping, move it to another QTH, use it mobile.
With battery option it weights only 44g so it can easily be flown on a Quadcopter, balloon or kite.

Low-pass filters sold separately, one set of the product "SMD and T37 Low Pass filter" is needed.


The WSPR-TX Mini works on any Ham band from 136kHz to 70MHz and is powered from 5V or a single LiPo cell.

Once you have set up your call-sign it will operate independently indoors or outdoors with minimal requirement of interaction from the user.
There is no need to have it connected to a computer, no need to set the time or to interact with it in any way. The WSPR-TX Mini takes care of everything needed automatically for you.


The GPS provides the timing necessary to ensure that the WSPR transmission is occuring at the correct time. The GPS also provide the position information needed to calculate the Maidenhead code that is transmitted. This is a great feature as it means the users don’t have to know the Maidenhead grid before getting on the air. This can be very convenient if you take the transmitter to a new location or use it in a mobile application.

The output power around 20mW so this is a low power tranmitter. This is still enough to get spotted and the low power gives it the ability to run for extended periods of time from a small LiPo cell. 
The low weight and power means it is the perfect WSPR tracker for ballons and other airial experiments. 
The current draw is 60mA when transmitting and 5mA or less when idle. (Future firmware upgrades may get this down to 0.5mA)
The onboard Arduino compatible microcontroller has the ability to measure the battery voltage. This information might be used in future firmware to hold off transmission when the battery voltage is low.


This unit has the potential for long duration fully autonomous operation with automatic tracking, timekeeping, charging etc.


Advanced but not high cost, minimal assembly required by the user.

To keep cost down and to minimize the amount of version I need to build and keep in stock I have not populated the Low Pass filter on the output.

The buyer will have to build this filter to complete the transmitter. Everything else is built, calibrated and tested.



For more information including links to the Source code and Schema - see the product page.


The product comes with the board built and tested.
Low pass filter and USB cable is not included.


Low pas filter #1021 is intended to be used with this product.
Optional 600mA LiPo board #1023 fits this product.



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