Amongst the mess is a complete software defined radio for 7.002 - 7.096 MHz. It uses $10-15 worth of discrete parts, including just 2 transistors. The 7.050 MHz local oscillator signal is split into two output signals, one 90 degrees out of phase. These feed two diode mixers whose output goes into a good quality sound card with a stereo input.
Alignment needs a continuous carrier signal - just adjust the phase splitter's two potentiometers to null the signal on the unwanted side of the carrier (I'm getting 30 - 35 dB down). Buildable in a few hours and requiring no test equipment to align, the result is a receiver that works suprisingly well, despite no front end RF filtering or amplification.
Note that the receiver is simpler than it looks - the 4 diode mixer on the matrix board is not used.
