We found this circuit in a 1976 documentation. The FET can be BF245 or MPF102 and the power supply need not be symmetrical. The FET in the feedback acts as an automatic gain control.
Using the HA2400 this circuit has its output voltage digitally programmed from the references...
Assembled with SMD components this circuit can be very small. The range is a few tens of meters. We...
This circuit can be used as a shield when its supply is 5 V. in this case we can exchange the...