This two-tube circuit, one being a double, was found in Radio Electronics magazine from July 1958. The distance to the microphone depends on noise and losses. The cable must be shielded.
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...