variable capacitor

[chikedef]

can l use a tuning capacitor on the radio receiver as a variable capacitor on my FM transmitter. wat is the range of the capacitor that is tha max and min capacitance

 

[k7elp60]

Yes you can. The tuning ratio of the the transmitter is generally the sq root of the capacitance ratio. The tunning ratio is the maximum capacitance/minum capacitance. If this ratio is 9:1 then the tuning ratio of the receiver will be close to 3:1.

 

[audioguru]

stray capacitance of the wires on the pcb increase the minimum capacitance of a trimmer capacitor.

 

[k7elp60]

Audioguru is correct, one has to take ineffect the stray capacitance...especially at standard FM broadcast frequencies.