We found this circuit in a 1977 National Semiconductor Databook. The circuit can use other FETs like the BF245 and has an input impedance of 10 megohms. The circuit gain is unitary.
This circuit checks the infrared emission of a common remote control. We found it in the March 1993...
This oscillator can run in frequencies up 10 MHz depending on the Power supply voltage. The 1 µF...
) This circuit is from a 1967 RCA SCR manual. The circuit uses components from the era that can be...