This is the receiver for the previous circuit found in the November 1991 Radio Electronics magazine. The frequency is 2.2 MHz determined by the coils.
This 80's circuit has been winning. It is a 1 000 gain sample and hold circuit and an offset...
The purpose of this 1-transistor amplifier is to allow the use of a milliammeter in an application...
We found this circuit in an old General Electric documentation. In fact, PUTs are not common...