The frequency of each note depends on R2, which must be replaced by a keyboard. The circuit is from Radio Electronics from April 1980. The power supply is 9 V for the amplifier used.
The quadrature oscillator is another type of phase shift oscillator, where each of the three...
The power supply shown in the figure provides output voltages in the range of 1.2 to 25 V with...
The frequency ranges that this receiver can tune in depend only on the coils. For medium waves L1...