04-05-2012, 02:43 PM
Transistor FM Transmitter
2 Transistor FM Transmitter.docx (Size: 248.7 KB / Downloads: 50)
Warning:
Take care with transmitter circuits. It is illegal in most countries to operate radio transmitters without a license. Although only low power this circuit may be tuned to operate over the range 87-108MHz with a range of 20 or 30 metres.
Parallel Tuned Circuit
A tuned circuit arranged as a parallel combination of an inductor and capacitor, will have a resonant frequency, Fr that is calculated with the following equation.
Calculators to Determine L or C Value from Resonant Frequency
Sometimes you may want to make a radio or tuned circuit to operate at a particular frequency, e.g. 14MHz. The resonant frequency formula can be used in reverse, enter your wanted frequency and then your inductor or capacitor value from your parts box to find the appropriate value.