The configuration shown allows to obtain a high voltage gain for FETs. FETs can be BF245 or MPF102. The circuit is from the 1977 National Semiconductor FET Databook.
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....