fm transmitter(completed) questions

poolman966554 said:

Also, can someone explain what the value of L1 is on pin9??

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L1 is a tuning inductor which helps set the resonant frequency of the RF oscillator. The PLL which controls the voltage seen across VC1 is what maintains the frequency set by the frequency select inputs. L1 is used to adjust the the resonant frequency in order to force the PLL to adjust the voltage of VC1 to 2 volts. This gives the PLL more room for voltage swing (0 - 5V) to lock in on the other frequencies offered by the chip.