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An OXO transmitter on 14MHz |
This afternoon I decided to build a 14MHz
OXO transmitter. As is often the case, I like to re-use old boxes and project parts, so the FETer box was photographed for posterity, then gutting and used for the OXO transmitter. In this version I did not go for full break-in and instead used a simple changeover switch, but added a push button net function to allow me to net the VXO without the PA being keyed. A small toroid in series with the crystal allows about 15kHz VXO range around the 14.060MHz QRP frequency. I used a 2N3904 for the oscillator and 2N3906 for the keying transistor and a 2N3866 for the PA, but may change this for 4 x 2N3904s in parallel for lower cost. My output is a little low at around 500mW.
It works fine with reverse beacon reports from Iceland and Slovenia and a nice 2-way QRP QSO with
IK2RGV who was running 5W.
The OXO really is a classic circuit: you just build it and it works. Another version is on the
QRPkits page.