This is the circuit of a modified Heathkit kit. The circuit was found in a Radio Electronics from December 1965. The author of the circuit included improvements to the original circuit.
This two-tone buzzer can be powered by a solar panel. The circuit is from a 1991 documentation. The...
Suggested by Radio Electronics from the 90s, this circuit is suitable for NiCAd batteries with a...
082E) We started with a simple Hartley oscillator circuit using a bipolar transistor that can...