Thursday, June 16, 2011

USB FM Transmitter Circuit for PC and Laptop

Here's a small FM transmitter ciruit for your desktop or laptop to enjoy the movie and music from a distance. This FM transmitter, which is powered by USB, recovers output on your computer or your MP3 player to the relay on the tape FM (frequency 108 MHz). For Assemblying this FM transmitter kit, an electronics hobbyist will have built in about 30 minutes.

FM Transmitter Construction
It is not necessary to drill the transmitter PCB. All components will be soldered to the plate with their legs folded.

The two transistors and the LEDs are polarized:
The transistor has a flat side, the LED a foot longer than the other is the anode (A), the other is the cathode (K). The audio cable (minijack) must be transformed from a stereo cable into a cable.

Mono Sound:
Soldering together the white and red cables, leaving aside the yellow cable (mass). The frequency setting will be turning the variable capacitor gently with a screwdriver or thin cardboard but rigid.

FM Transmitter Parts List
* 1 Ohm resistor 510 (green - brown - brown)
* 100 resistor 1 kOhm (brown - black - yellow)
* 1 MOhm resistors (brown - black - green)
* 1 capacitor 0.1 uF (0.1)
* 1 nF capacitor 47 (0.047)
* 1 capacitor 4.7 pF (479)
* 2 pF capacitors 22 (22)
* 1 variable capacitor 1.5 pF ... 15
* 2 transistor BF 246 (F246A)
* 1 red LED
* 1 audio cable (minijack)


  1. hey,bro,im from bangladesh like you.i also make many things like you,but not good as you..i cant make this,bro please, can you make a this cirkit for me??please bro contact with personal number=>8801196260311, facebook and email

  2. ভাই, আমি এরকম জিনিস বানানোর বহু চেষ্টা করেছি, কিন্তু বারবার ব্যার্থ হয়েছি। আমি ময়মনসিংহে থাকি। তাই আমার মূল সমস্যা পার্টস পাওয়া নিয়ে। এ ব্যাপারে যদি আপনি আমাকে কোনভাবে একটু সাহায্য করতেন তবে আমি আপনার প্রতি খুব কৃতজ্ঞ থাকবো। আমার অনেক দিনের একটা শখ পুরোন হত।
    আপনাকে অনেক ধন্যবাদ।

  3. what the size of the pcb

  4. স্বদেশ
    ভাই আমিও তাইফুর ভাই এর মতো try করসি but সফল হতে পারিনি।এ ব্যাপারে যদি আপনি আমাকে কোনভাবে একটু সাহায্য করতেন তবে আমি আপনার প্রতি খুব কৃতজ্ঞ থাকবো।
    আর এটার renge তা একটু জানাবেন।আপনাকে অনেক ধন্যবাদ।

  5. can use na jack for the supply instead of the usb port

  6. hey boss! Thank you very much for this kind of project. but one thing I want to know that in your pcb layout you have metioned a componenet named "pont", what is it? I didn't get that. Pls let me know, thank you again.

    1. Port, as in usb port.
      Or do you mean 'sont' in the text which means transformer printed on pcb?

  7. the "pont" is wire that jumper to connect to negative battery to source sound..ok...

  8. What's is the KILOMETER radius

  9. What's is the KILOMETER radius. I am interested.
    Here's my mail:

  10. what is the size of the work piece? Does the pont mean jumper of wire of what thank you.The work is so nice

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