Amplifier stage with the T411E (T411E)

The pentode tube used in this circuit has 1.5 V filament. The circuit is a voltage amplifier with the 1U5 tube.

VCO 4049 (CB15463E)
A simple version of VCO CMOS using 4049 inverters is shown in the figure. This circuit can be...
aaaa SCR oscillator for code practice (CB8795E)
This simple SCR relaxation oscillator was indicated by a 90s Popular Electronics. The frequency is...
Customer Service Counter (CB6141E)
This circuit can be used as an answering password system in a store, office, or other location....