This circuit of a Popular Electronics from the 90s makes use of components of the time. The circuit has sampling and retention capabilities and a conversion rate of 1V / kHz.
The oscillator shown generates a rectangular output signal at a frequency of 5 MHz, determined by the...
Found in a Popular Electronics - January/February 1969 this circuit was intended to increase the...
Found in a radio amateur magazine of the 1980s, this circuit uses components that can still be...