This low noise preamplifier has a gain of 19 dB in the 30 MHz band. The circuit is from the 80s. Transistors are from the era, and equivalents can be used. The circuit consumption is 13 mA.
The existence of field effect transistors at the input of the integrated circuit (operational...
This circuit turns on an old cassette recorder when the telephone rings, thus enabling the...
Found in Radio Electronics from the 90s, this circuit can vary the frequency in small values...