Preamplifier (T918E)

This 3-tube circuit has two inputs. The circuit has the indicated supply voltages and two inputs that can eventually be expanded.

Voltage Variator LM3900 (CB5057E)
In the figure we have a circuit that allows us to obtain a variable voltage of approximately 0.5 to 25 V...
TTL Pulse Transmitter (CB4164E)
The purpose of this circuit is to emit infrared pulses. However, LEDs for visible light can also...
3 Tone Oscillator (CB4187E)
This circuit appears in other articles and suggestions for circuits in this section from other...