Long Range Fm Transmitter And How to work

FM Transmitter is a fun project.

This is an attractive device for the child.

need a long-range FM transmitter?

Then you just have to follow some rules

Actually, how is it Working?

What mystery is hidden behind it?

let's see a basic proses to make an FM transmitter.

In this basic, you will understand this batter.

FM transmitter is divided into two parts, the first one is Amplitude Audio frequency and 2nd will produce carrier wave.

every sound  frequency is electrical plus

when sound rises up that means electrical pulses will amplitude, or you can call it an electrical Wave.

let me show you a demo.

see I put an audio jack in my laptop and the other end to my baby oscilloscope.

and play some music and you can see the electrical pulses.

I know the Graf is very messy.

when we play any song, there are so many different types of frequencies that look messy,

so I think you guys having difficulties understanding this.

ok, let's see another way to clear this.

now i play some 50 hz frequency tone

and here you can see the 50hz beautiful sine web.

if I slowly increase the volume then the signal will slowly amplitudes.

condenser Microphone works in the same way as Audio Plus,

ok, let’s see how to produce Resonance frequency.

if I attach a ceramic capacitor with an indicator and put in some volts then this circuit  produces some

resonant frequency web.

this type of circuit is called a tank circuit.

but here is a problem.

this circuit can produce frequency for a little amount of time.

because in this case, we face a max power drop.

when this circuit is powered up, it makes this type of resonant frequency.

at first time this frequency is amplitude and slowly goes down to 0.

we need some components that can produce a constant amplitude resonant frequency.

That's why you need a transistor that can make amplitude-frequency.

this circuit needs some resistor to active the transistor

and for stable frequency, you need some kind of ceramic capacitor.

here this capacitor works as an inductor feedback.

and then it will produce constant resonant frequency.

which frequency do you need to transmit on your FM radio, That is why you need to put this formula

in this basic, I make an indicator 4mm by 5mm.

and take all the components that we need to make this FM transmitter.

first, I put here a 3.5mm socket for the transmission external audio sores.

on the other hand, I put two tiny switches one for the on of and another one is mic and external audio.

here you need some ceramic capacitors for the feedback process, producing resonant frequency, volt filter, and antenna filter.

Also, you need a trimming capacitor, this is optional, leave if you don't wanna use it, not a problem

this capacitor is only for producing different mhz transmissions.

even I put some resistors for transistor oscillating and stop unwanted sound web.

and don’t forget to put an electrolytic capacitor for a smooth sound web.

for voice transmitting I put here a condenser mic.

and also put an LED to see a proper power-up signal.

In the end, I use here a cl1005 transistor

I use this transistor for better FM transmitting and long-range.

 after completing all hardware work now time to check how it will work.

now time for the phone,

and connect an external spiker with this Phone to produce a loud sound.

I open the Radio application on my phone.

Besides I connect a 9volt battery with this fM transmitter.

and turn on the FM transmitter power switch.

And the LED indicates that it is on.

There are two ways to connect this device

the first way you can search for the transmitting frequency on your phone or something else devise.

and 2nd way to connect by trimming this capacitor.

and also you can switch external audio sources such as a laptop and cell phone or something like that.

I hope it can transmit good-quality audio.


DIAGRAM

GERBER files  Download




COMPONENT 


#1#  condenser mic

#2#   3.5 mm socket

#3#   CL1005 Transistor

#4#   4.7k Resistor

#5#   2.2k Resistor

#6#  10k Resistor

#7#   220Ohm Resistor

#8#   22pf ceramic capacitor

#9#  6.8 pf ceramic capacitor

#10#  102 ceramic capacitor

#11#  1uf electrolytic capacitor

#12#  LED Yellow

#13#  30pf trimmer capacitor

#14# 100nf ceramic capacitor