We found this configuration in a 1974 publication. Transistors can be replaced with equivalents such as 2N2222. The circuit has a dynamic range of 60 dB.
This filter rejects 1 kHz signals, being suggested by the manufacturer of the operational...
This is a simple variac type source found in the July 1962 Radio Electronics magazine. Voltage and...
The current of this source is 200 mA at the most, and the output depends on the zener that may...