This circuit with 4 transistors can receive signals in 6 shortwave bands. The circuit is from a Radio Electronics from May 1958. The output is for high impedance headphones.
We present a circuit formed by six voltage comparators. Each comparator will analyze the voltage...
This circuit can generate time base signals from 5 to 1500 Hz. We find it in a documentation about old neon...
In this circuit the CA3140, an operational amplifier, is used as a comparator with the zener diode...