This circuit with 4 transistors can receive signals in 6 shortwave bands. The circuit is from a Radio Electronics from May 1958. The output is for high impedance headphones.
This oscillator for telegraphy practice was published in Radio Electronics magazine in March 1958....
Found in documentation two years 80, this toy instrument uses an integrated circuit little...
We found this circuit in a Radio Electronics from July 1968. The circuit generates rectangular pulses...