Found in a Popular Electronics from the 90s, this circuit is intended to measure the harmonic distortion of an audio signal. The circuit can be tuned between 970 and 1030 Hz.
This VHF transmitter was found in Radio Electronics magazine from June 1964. The transistor is an...
This two-transistor circuit is from a Radio Electronics magazine from April 1965. The transistors are...
This circuit was found in a 1967 documentation. The switch diode is a component of the time and is...