A minimalist CW transmitter built in less than ten minutes ( vers. 2025 ). With only a handful of components and a power output of 550mW @ 12V or 350mW @ 9V. A great project for beginners in building amateur radio transmitters. I found the schematic in the Minimalist QRP Book. Miguel PY2OHH also built a version of this simple and cute CW transmitter. In the video you have the first test of the transmitter with no low pass filter. On YouTube I also have a 20m band version and other versions of the transmitter. The 20m version was only experimental and I was not so happy about the results so I decided to only stick to the 40m band version. The circuit works as a low-power oscillator, capable of reaching 1W and currents of 100mA ( remember that the 2N2222 is for 80mA ). The transistor handles this current well in CW, but don't keep the key activated for too long as the transistor will burn out. Another problem is operating without an antenna or a dummy load, the transistor will burn out. At some point I used a metal can 2N22222A with heatsink, but the power output was not so great so I returned to the basics and changed back to the original TO-92 version. This minimalist CW transmitter is the base of the Pititico CW Transceiver. The schematic is slightly modified from the original so it can be used with lower voltage as well. I would recommend 9V with 350mW as the transistor doesn't heat up so much. C2 allows you to tune the transmitter slightly. I added this one so I can tune it exactly on 7.030MHz. You will have to provide the external hardware. PCB Way will not provide these on the assembled version. More details in the Blog Article.

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