This interesting circuit uses a sodion valve that we have already described in an article on the website. The circuit uses several batteries for power. The phone is of high impedance.
This converter converts a signal in the 200 kHz to 3.8 MHz band into frequency signals that can be...
This is the receiver for the previous circuit. The audio amplifier supports equivalents. The...
This circuit is from Radio Electronics from February 1987. The frequency is given by the crystal that...