neazoi
Advanced Member level 6
Hi, I need a very stable audio oscillator circuit that operates at a single frequency somewhere at 30Hz.
Square wave is preffered and stability is the key point, since it will be used as a reference to lock a higher frequency oscillator.
I would use a multivibrator, but how stable it should be if using low ppm resistors and capacitors?
In that case, can it be made so that the timing resistors are made high and the capacitor very low values?
I am asking that because it is easy to find very low ppm resistors, but only capacitors up to a few nF can be made NP0.
Some ideas are here, how about the high stability version of figure 3?
https://www.nutsvolts.com/magazine/article/bipolar_transistor_cookbook_part_6
Square wave is preffered and stability is the key point, since it will be used as a reference to lock a higher frequency oscillator.
I would use a multivibrator, but how stable it should be if using low ppm resistors and capacitors?
In that case, can it be made so that the timing resistors are made high and the capacitor very low values?
I am asking that because it is easy to find very low ppm resistors, but only capacitors up to a few nF can be made NP0.
Some ideas are here, how about the high stability version of figure 3?
https://www.nutsvolts.com/magazine/article/bipolar_transistor_cookbook_part_6
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