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 transistor amplifier from the 1950s had gain of 10. The circuit is from Radio Electronics, from the...
This was a very popular instrument in the workshops of the 60s and 70s. It was a "top of the line"...
An excellent low frequency sine signal is produced by this oscillator. The frequency is determined by the...