output of BFSK is high frequency for high modulating input and low frequency for modulating input 0.
but when we do in practical, we got high frequency for modulating input 1 but same frequency for input 0. iam attaching the circuit diagram with this. instead of pnp transistor im using npn. we design for frequencies 1000- 1200 Hz.
npn, when the transistor (Q1) is ON, Rc || Ra ; ie frequency increases.
when Q1 off, Rb C plays ie, frequency decreases. (it acts as astable)
for low modulating input i cant obtain low frequencies. (we obtain same frequency as input)
but when we do in practical, we got high frequency for modulating input 1 but same frequency for input 0. iam attaching the circuit diagram with this. instead of pnp transistor im using npn. we design for frequencies 1000- 1200 Hz.
npn, when the transistor (Q1) is ON, Rc || Ra ; ie frequency increases.
when Q1 off, Rb C plays ie, frequency decreases. (it acts as astable)
for low modulating input i cant obtain low frequencies. (we obtain same frequency as input)
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