WEEKEND PROJECT
A 1.5V Minimal Art Receiver

Here is a direct conversion receiver for 1.5 V single battery cell. This receiver is designed for high impedance headphone operation. The mixing is done in the oscillator stage by coupling the antenna to a input transformer in series with the quartz crystal. The antenna side of the transformer has 3 windings for best 50 ohms matching (sec, see picture). A 5k trimmer is used for optimum performance. The VXO frequency is pulled by a small capacitor which allows a few kHz tuning range. The AF output signal is surprisingly loud and clear.