We found this circuit in a 1960 Radioarama magazine. The instrument tests common general-purpose transistors indicating their gain on a moving coil instrument. The loop serves to adjust the circuit.
This is a Japanese commercial radio from the 60s. The circuit is listened to by phone and is...
The first circuit we present is ideal for matching the low impedance of transducers, such as...
We found this circuit in Motorola's Linear Databook in 1990. The component used is not common today....