This untuned (aperiodic) amplifier circuit was found in the August 1974 Radio Electronics magazine. The transistors are period, and the board layout is critical.
Found in a publication by Gernsback from 1960, this circuit makes use of germanium transistors of the time....
To control relays or DC motors safely with double isolation via the parallel port, we suggest the...
This circuit is from a 1975 Sperimentare (number 11). The circuit uses optical coupling for a...