Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Because America was the first country to have FM radio stations then they decided to use a lot of pre-emphasis to reduce hiss. In those days microphones and recording equipment produced few high frequencies. Then later when Europe began using FM stations the microphones and recording equipment had more high frequencies and they decided to use less pre-emphasis so that there is less over-modulation. America kept their "mistake" and Europe used their different pre-emphasis.1 why c4 is different?
The audio signal from Q1 to the base of Q2 amplitude-modulates the base voltage of Q2. When the amplitude of the base voltage of Q2 is modulated then the changing voltage causes its capacitance to change. The changing capacitance changes the frequency of the oscillator which is FM. FM radios ignore the small amount of AM.2 how signal from q1 modulates oscillations due to q2 producing fm?
A 9V battery voltage drops to only 6V or less during its life.3 why regulator is used?
Q2 is a Colpitts oscillator circuit. Q3 is an RF amplifier and buffer so that the oscillator frequency does not change when something moves toward or away from the antenna. Other circuits are Hartley or many other types.4 why q3 is used as colpitts oscillator again?
R1 powers the Jfet inside an electret mic. If R1 is removed then a dynamic mic (coil and magnet) can be used.5 can we use other mic in place of electret in this circuit?
I used books when I went to school and university 48 years ago. In the seventies I bought The TTL and The Cmos Cookbooks by Don Lancaster.The Art Of Electronics is a good book today.6 which are best books for analog electronics,digital electronics,communication systems and network analysis and synthesis?
you want to use the audio input of the FM modulator for the purpose, why do you need a VCO on FM range? your receiver will be tuned to only one frequency but the audio input can be from a low frequency VCO.
or you can think about coding the value to multiplexed tones as a digital bits.
1) Remove L2.
2) Connect the anode of the varactor diode directly to the collector of Q1, not to its emitter.
3) Reduce the value of trimmer capacitor C2 by the capacitance of the varactor diode.
4) C4 causes the transistor to be a common-base oscillator and must be used.
:
Your schematic is much too big and the lines on iyt are almost the same color as the dark background so i cannot look at it.
Use a schematic drawing program.
I make schematics and copy parts of other schematics with Microsoft Paint program. Then I save it as a PNG file and attach the file to my reply here.