This site is the home of the mcHF QRP transceiver. It is a small, home-brewed amateur radio project. Firmware is released as open source and most project files are released as well, with the only restriction of not commercial use (manufacturing and sales of kits or complete product).
Looking at the block diagram (Fig1) it should be clear that my design goal was to make it as cheap as possible – without sacrificing functionality – and include the ability to add new features via simple software update.
The choice of architecture is a direct conversion receiver and transmitter, with a small micro-controller to provide control and DSP functions. The analog blocks in this implementation were kept to the bare minimum. Shifting, as much as possible, functionality into the digital domain. Some datasheets with more detailed description of the design concepts of individual blocks are available at the Downloads page.
- Standalone and compact embedded transceiver
- Continues RX coverage 2-30 Mhz
- 5W output power
- CW, SSB, AM and FM – transmit and receive
- 300/500 Hz CW and 1.8/2.3 kHz SSB filters with adjustable passband centering
- 3.6 kHz “wide” filter plus 5, 6, 7.5 or 10 kHz “extra wide” filters for SSB/AM reception
- SSB/AM Transmit Speech processor
- DSP noise reduction
- DSP automatic notch filter
- Spectrum scope
- Waterfall Display
- Highly configurable with a wide variety of menu items
It took some two years to the moment i can offer the mcHF in kit form. It consists of two boards with populated SMD parts and extra components supplied in plastic bags. The kit does not include speaker, final MOSFETs and enclosure.
It is worth pointing out that the kit requires some advanced soldering skills and knowledge in electronics as mods might be required. Also extensive tuning and calibration might be needed, or sometimes debugging of problems. It is not recommended as first kit or if you expect to be on the air after few M3 bolts tightening.