Instructables

Make a 1.5v Single-Transistor FM Transmitter

Picture of Make a 1.5v Single-Transistor FM Transmitter
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Hello!

I'm gonna show you How to make a Simple FM Transmitter that works with only an AA battery.

Components:
47 pF Ceramic Capacitor x1
33 pF Ceramic Capacitor x1
10 pF Ceramic Capacitor x1
22 uF Electrolytic Capacitor x1
2SC655 (or BC548) Transistor x1
Single Battery Holder (AA Size)
small Breadboard/PCB
10cm Magnet wire x2
Audio Signal Source (e.g. a MP3 Player)

Tools:
Soldering Iron
Solder
 
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Step 1: The Circuit and Parts

Picture of The Circuit and Parts
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Here is the Circuit we're going to make.

Step 2: Start Soldering Parts on PCB

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It takes about 10-12 mins to do this.

Step 3: Make the Coils

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Wrap the first Magnet Wire around a thick pen or a size AAA battery.

Do the same for the second Magnet Wire, too.

...Then Solder them on PCB

Step 4: Final Steps

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Solder the battery holder wires, Antenna Wire, and the Audio Source.

Step 5: Turn on your Radio

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Turn on a radio and set it at 89MHz FM
Connect the "Audio In" of the Transmitter to your MP3 Player (or any other non-amplified things playing music).
Place the Battery in the holder.

Enjoy!

How can I change the frequency of the emitter?I guess it depends on one of those capacitors..but which one?

It is NOT the capacitors (however, the Farads matter) the frequency is changed based upon the oscillation of the inductors (the coils of wire) if you want to change the frequency, search the internet for a calculator that to find how many turns of wire you'll need for a specific frequency.

dmarcelo23 months ago
qual e o concumo??
imaduddin6 months ago
how the magnetic wire diameter?
avashisht110 months ago
how is the sound quality???
lseemann10 months ago
nice gag, is it a stereo transmitter or only mono?
vicenzio2012 months ago
but the receiver as lai made?
parmar_cd1 year ago
There is a problem in this circuit, every time frequency is change when you move the circuit. Can i put variable/trimmer capacitor in this circuit. If yes where to put the variable capacitor and which type of capacitor. Thanks
how to increase the range of transmitter.
jumper11111 year ago
What's the range of this transmitter
~CableGuy (author)  jumper11111 year ago
About 10 meters max!!!
tutdude981 year ago
Where did you get pcb
~CableGuy (author)  tutdude981 year ago
My uncle is owner of an electronic components selling website. I gave him the circuit and asked for a PCB.
I Had salvaged the components before from an old cordless phone.
Would a nte199 work for the transistor?
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