This circuit for the 40 MHz band was published in Radio Electronics magazine in December 1957. Its purpose was to monitor the signals of the Russian satellite launched at the time.
This circuit, with the help of a 15 V x 1 A source, allows to measure small resistances,...
This circuit uses a piezoelectric transducer to produce sounds like a buzzer. Frequency is...
We found this circuit in a Texas Instruments optoelectronics manual. The audio modulator serves for...