LM3900 Amplifier (CB25165E)

This circuit with Norton operation is from an article in Radio Electronics magazine. The gain is given by the resistors.

Microphone Signal Conditioner (CB15601E)
In the figure we present a circuit of a microphone signal conditioner using the SSM2167 integrated...
Tunnel Diode Spy Transmitter 4 (CB14865E)
This transmitter emits signals in the FM range, reaching a few meters away. The modulation...
Voltmeter with 200 M ohm Input (CB11248E)
This circuit was obtained in an English publication of 1993. It is an amplifier for...