This circuit is from Mullard 1969 documentation. The circuit operates at a relatively high supply voltage and has a 10 Vpp output. The transistors are of the time, but admit equivalents.
The 556 integrated circuit is actually a double 555. This circuit can be assembled from an...
The transducer used in this configuration that appears elsewhere on this site is a piezoelectric...
This modern XTAL radio replaces the galena crystal for a germanium diode as the 1N34 or...