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The Theremin has two very high frequency oscillators (around 350 kHz). One of them is fixed, and the other is varied by the capacitance of your hand: it's the difference between the two frequencies which decides the pitch.
29 Δεκ 2004 · The theremin is played by carefully moving your hands near 2 antennas, one for volume and one for pitch. But how does it work? If you mix the signals of 2 rf oscillators, you will get many output signals. The most important signals are the sum and difference of both frequencies.
Depending on your hand position and the adjustment of the instrument, the beat frequency can be anywhere from around 65 Hz to about 3 kHz (260 kHz minus 257 kHz). These are audio frequencies, and they correspond to a range that spans from about two octaves below middle C to about three-and-a-half octaves above middle C.
The expected frequency is around 70 kHz with just the fixed capacitor. When you put in the variable capacitor, the frequency reading should change as you change the capacitance (see the video below). The output on the oscilloscope should be a square wave.
Calibrating the Frequency Signal The frequency range for the Theremin should be at least two octaves (220 to 880 Hz). A second LabVIEW subVI called Scale Frequency.vi, as shown in Fig. 5, converts the second photometer signal level into a frequency level. The photometer input (0 to 6 V) is converted into an audio
20 Οκτ 2022 · Depending on your hand position and the adjustment of the instrument, the beat frequency can be anywhere from around 65 Hz to about 3 kHz (260 kHz minus 257 kHz). These are audio frequencies, and they correspond to a range that spans from about two octaves below middle C to about three-and-a-half octaves above middle C.
27 Ιουν 2024 · The complete JFET-based theremin circuit includes a second oscillator, a mixer, and a circuit for the volume antenna. The second oscillator is stabilized at 470 kHz by a ceramic resonator, and so it must be possible to set the adjustable oscillator to this frequency.
