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Dirk275 edited this page Mar 25, 2021 · 49 revisions

Welcome to the UHSDR Project Wiki!

This wiki will serve as a community edited clearing house of information regarding firmware on all UHSDR (Universal Ham Software Defined Radio) supported radios such as the mcHF TRX, MiniTRX and OVI40 TRX. The UHSDR software was originally started as mcHF firmware, so a lot of information is dedicated to the mcHF. Most of this applies to other supported radios (since they share the same firmware, with differences).

Internal wiki pages are listed in the side box to the right.

Binary builds for this repository are available here .

For the impatient we have the Quick Operating Guide

Building your UHSDR TRX


If you want to start building your ham SDR, the mcHF is a mature design with (partially built) KITS and PCB available for sale from the original designer and a recommended choice.


The OVI40 SDR has been designed by the OV I40 development team. Discussion forum here, ordering here, wiki here.

The mcHF

There are currently several good sources of information on the mcHF. The first is of course Chris's webpage. There is also an mcHF group on where most of the development discussion occurs. The files section of this group contains a wealth of community supplied documentation and modifications.

Building your own mcHF is a lot of fun (and stress) and can be done by any motiviated ham. Yes, it is mostly SMD, but soldering SMD is no more complicated than soldering wires, tools for SMD soldering are not expensive (a good soldering iron is enough). Yes it is about 400 items and 1 of these has 100 pins, but if you buy a prepopulated kit from Chris M0NKA, this goes down to a few dozen rather simple items to solder.

Learn more

Before using the TRX it is strongly recommended to run the appropriate adjustment procedures in order to have calibrated output, proper signals, etc. Don't skip over this section.

Using the UHSDR Firmware

The following part provides you with information how to operate and maintain a UHSDR TRX. See this as an attempt to move away from the very nice mcHF manual made by Clint, KA7OEI, which you can find here. The document from Clint is based on a very old mcHF firmware version ( and is partially outdated by our continuous work on the firmware. Still the document is worth reading, as is the quick manual but you should have a look at the following links first.

Explains which button / touch actions does what. Strongly recommended read!
The all menu items are explained in the Operating Manual Menu!

The UHSDR firmware provides CAT control and also audio (demodulated audio or even 48khz IQ) via USB. This page tells you how to use it.

Most of the bits that make a UHSDR hardware a radio are performed in software using DSP techniques. As such, keeping the firmware up to date is critical to getting the most from your radio. The latest code will be found in the git repository started by DF8OE, which also hosts this wiki. There is a single branch of code for the UHSDR under active development but different kind of releases:

  • Stable Releases: Newcomers and first time builders of the radio should use stable releases first. If the second part of the release version is an even number, it is a stable release.
  • Development Releases: The newest features will be seen first in the active-devel branch. From time to time releases are made, either for preparation of new stable releases or in order to test new features with support of the community. If the second part of the release version is an odd number, it is a development release.
  • Daily Builds: Bleeding edge code, this is where the contributors code is integrated.
  • Other Branches/Repositories: Individual developers may contain code under very active development and may not even compile properly on every system. Those familar with open source projects will be familiar with the UHSDR development model.

Prebuilt binaries including daily builds for the latest releases are available from ( Older Releases are available using the "Releases" link in Github. Please make sure that the firmware your are trying to use, fits the hardware of your TRX. Different variants will have different names. The UHSDR bootloader "knows" the right name of your firmware (from the filename) and will not load other firmware files. ATTENTION: If you rename a file to the expected name of the firmware, the bootloader will flash this file as firmware without further checks.

Learn more


The heart of any open source project is the contributions by individuals. Source code for the project is using git currently and can be found here. There is a good explanation of github workflow here that is worth a read before branching and hacking on the code. And an online book written directly from the git creators you can find here.

We have specific instructions for contributors collected in guidelines for contributing.

If you think, the UHSDR firmware is missing some cool feature, you could simply program it yourself. Start with setting up your development environment. It is easy and it can be done on Linux, Windows or even Mac OS X.

Clone this wiki locally