Short Rage Wireless Music Transmitter

Now , i am with a short range wireless FM transmitter which can powered through USB. It can take audio signals and transmit it over a short . It's maximum rage is around 100- 150 meters.you can easily listen it over a radio . it's very cheap and easy to build.

Step 1: Fetching Parts

All you need are some common electronic components.
You can buy them at Radio Shack!

1. Transistor BC 548 OR 2N2219a.

2.Capacitors : 1n , 1n , 10p , 10p variable , 1uF electrolytic.

3. Resistors : 2k7 or 2.7 k , 1k , 10k , 10 variable.

4. Inductor : you can make by yourself . 7 turns on 3mm or  6 turns3mm.

5. Battery : 9 volt .

6.  PCB you have to make one or use breadboard.

7. Antenna 10 cm long!

8. Nothing else

Step 2: Circuit Diagram

Here is the simple circuit diagram!

Step 3: PCB - LAYOUT

Here is the PCB layout.
In the next PCB  the red ones are capacitors , green ones are resistors , brown one is variable resistor , white one is transistor , yellow one is inductor and other holes are for power and input and antenna. TO make this PCB at home you have to follow this link : ""https://www.instructables.com/id/DIY-Printed-circuit-board/"".

Step 4: Finished Product

HERE is the finished product!

Comments

[pfantastic]

this looks great, but it's just one audio channel, right?

[vietanisme]

Wow, that's was exactly what I want. How far can it transmits. And what's the inductor's inductance. Forgive me if I am disturbing you.

(I think my English isn't well :) )

[ubdussamad]

And don't mess with inductor just make it as said cause i don't remember it!

[vietanisme]

But I still don't know what is the wire's diametre. You couldn't make it without having this number in mind, right.

[ubdussamad]

Well it's nearly a whole house (not if your house is full of complex radio frequencies and disturbances). It's like 5-10 meters.

[benaraujo]

hey.. firstly i want to thank you for this amazing build.. i wanted to know how much power does it transmit over the antenna.. because in my country, transmitting over 500mA is considered illegal and i don't wanna break any rules.

thanks..

[ubdussamad]

No worries it's way down that that range may be one or two houses.

[sol-bear]

What is the USB plug for? it is not on the diagram, it can not be for power as that is 9V.

[ninja9]

sorry to bother u.. are we using variable resistor too? if yes, we r varying both resistor and capacitor at a time to set a frequency?

[ubdussamad]

no! the variable resistor is for controlling the volume! to change frequency you have to change the capacitance of the variable capacitor!

[ninja9]

u didnt mentioned the range of frequencies it is transmitting

[ubdussamad]

You are right because the frequency is variable you can tune it by C2 capacitor!

[ninja9]

it is not a receiver(a receiver can be tuned).. its a transmitter.. so it should emit with some fixed frequency.. and how to tune it?with physical means?

[ubdussamad]

Oh dear lord! Let me explain this: The receiver circuit given in this instructable does not have a fixed transmitting frequency. The frequency of transmission can be controlled by changing the value of C2 which is a variable capacitor ! Just change the value of the capacitor and the frequency of transmission changes respectively.
Hope this clears you doubt if not tell me and explain your problem well!
Thanks for Commenting!
I like people who make me angry by asking questions!

[The Brilliant Empire]

Can you be more specific with the remaining holes? What exactly goes to what? Thanks

[The Brilliant Empire]

The holes that are circled in purple? Just need some clarification

[ubdussamad]

Some of the holes are for the USB 2.0 male jack for getting power and antennas and other power supplies!

[PirateLabs]

Very cool and well done. This is a very useful item.

Thanks.