Found in a1967 Ferranti documentation, this circuit uses an operational amplifier from that time. The circuit uses a LDR as a sensor and has a null setting.
This circuit for RF signals was found in the March 1987 issue of Radio Electronics magazine. The...
We found this circuit in Texas Instruments' Linear Circuits Applications. It is a low consumption peak...
This medium wave radio must use a high impedance piezoelectric, crystal or magnetic phone and the...