This circuit is from an Electronics World of 1968. The transistors are of the time and the power is supplied with a voltage of 40 V. The circuit is high fidelity.
Found in old National Semiconductor documentation, this indicator uses an integrated circuit from...
Other amplifiers of the series like the MC3301, MC3401 and LM2900 can be used in this circuit. We found...
The microwave sensor of this circuit is a common ceramic capacitor. The circuit is from an 80's...