With this circuit, signals in the range of 10 kHz to 150 kHz can be received at close to 4 MHz from a shortwave receiver. The circuit is from a 303 Circuits from the 90s.
This interesting circuit, found in an old American publication, measures alternating signals in a...
This sophisticated audio generator with digital display was found in the March 1984 issue of Radio...
This power supply is from a 1977 documentation. The transformers have 11 V secondary with 10...