Found in a 1924 publication, this 2-valve receiver has a speaker output. Power comes from several batteries. Information about the coils is given.
This circuit was found in the ON Semiconductor's Thyristor manual of the 1980s. The high quality...
This simple injector circuit can actually be powered by voltages from 3 to 9 V. The frequency is...
This 10 kHz filter is based on a 741 operational amplifier. The circuit is from Electronics Now...