Super Yet Simple FM Transmitter Circuit

by ahmedebeed555 in Circuits > Electronics

3280 Views, 14 Favorites, 0 Comments

Super Yet Simple FM Transmitter Circuit

FM.jpg

Welcome to my instructable. Actually this FM Transmitter is from the past. It is actually from the year 2001. I saw the pictures and files so I wanted to reconstruct it as a useful instructable.

I'll be adding so steps and photos. So stay tuned.

You can read about this project in Arabic on my blog Here

http://idea-arabic.blogspot.com.eg/2015/11/fm-tran...

In 2001 I decided to build my own FM transmitter. I didn't look for something fancy or very long range. I started to look for a working circuit inside books on the university library but no help.

I found large circuits with complicated designs. I even had no guarantee that they will ever work. So I've decided to go online and search for something that is already tested to be working.

While you can nowadays easily find good and less expensive FM Transmitters for sale, I wanted to make my own to learn how they work.

So I've decided to build it.

Wish you the best. And have fun ,Live free And Read Books on Amazon

Here is my Channel on Youtube:

AeroArduino


The Circuit

fm.gif
fm3.JPG

I found this circuit and decided to start building it.

http://www.aaroncake.net/circuits/fmtrans.asp

Components

Part Total Qty. Description Substitutions vendor

C1 1 0.001uf Disc Capacitor Amazon, eBay or Banggood , Aliexpress

C2 1 5.6pf Disc Capacitor Amazon, eBay or Banggood , Aliexpress

C3,C4 2 10uf Electrolytic Capacitor Amazon, eBay or Banggood , Aliexpress

C5 1 3-18pf Adjustable Cap Amazon, eBay or Banggood , Aliexpress

R1 1 270 Ohm 1/8W Resistor 270 Ohm 1/4W Resistor Amazon, eBay or Banggood , Aliexpress

R2,R5,R6 3 4.7k 1/8W Resistor 4.7K 1/4W Resistor Amazon, eBay or Banggood , Aliexpress

R3 1 10k 1/8W Resistor 10K 1/4W Resistor Amazon, eBay or Banggood , Aliexpress

R4 1 100k 1/8W Resistor 100K 1/4W Resistor Amazon, eBay or Banggood , AliexpressAliexpress

Q1, Q2 2 2N2222A NPN Transistor 2N3904, NTE123A Amazon, eBay or Banggood , Aliexpress

L1, L2 2 5 Turn Air Core Coil I'll show you how I made them in the next step

MIC 1 Electret Microphone Amazon, eBay or Banggood , Aliexpress

MISC 1 9V Battery Snap, PC Board, Wire For Antenna Amazon, eBay or Banggood , Aliexpress

The Coil

IMG_20170404_192734.jpg
IMG_20170404_191604.jpg
IMG_20170404_191517.jpg
temp_1367117093.jpg

I made the coil from a thin insulated copper wire. I got the wire from an old destroyed transformer.

Then turned on a pen tube. This is a very simple step. You just need to make 5 turns of wire over the pen tube, then cut the wire.

You need to solder the coil into the PCB and at this process the coating on the copper wire will be removed. So you don't have to worry about the thin insulation around the copper wire.

Connect the Circuit and Test

fm1.gif
FM.jpg
Cover Wind.jpg
Cover Learn.jpg

I connected the circuit on a piece of copper perfboard and installed it inside an old Cassette Tape box.

You can see the 9V battery connector and the variable capacitor knob.

Now you can test the circuit by connecting the MIC and talking into it. To receive the signal, you need a standard FM Radio Receiver.

You need to tune the Receiver and the Transmitter by trial and error until you get the signal.

The range of this FM transmitter is about 90 meters.

Thank you for reading my instuctable

Here is the article in Arabic on my blog.

http://idea-arabic.blogspot.com.eg/2015/11/fm-tran...

Thank you for reading my instructable.

Do you like audio books and want to learn something new on the Go ?

This instructable is brought to you by Audible, the famous Audio Books Platform. You can now listen to free Audio Books from Audible.

Listen to Free Audio Books on Audible US ...

Listen to Free Audio Books on Audible CA ...

Listen to Free Audio Books on Audible UK ...

Listen to Free Audio Books on Audible DE ...

Listen to Free Audio Books on Audible FR ...

If you want to support us, you can do so through checking our books on kindle.

Wish you the best. And have fun ,Live free And Read Books on Amazon

That's all. Thank you for reading.

Here are some of my latest books on Amazon.

Learn By Making

Backyard Wind Turbines