Categories: Radio

9V FM Radio Transmitter

Here the simple and low cost FM transmitter circuit. The frequency range of this FM transmitter should be about 89MHz – 109MHz. Output power is about 9mW at 9V.

Components List:

Resistors:
R1, R6        : 12K
R2, R4        : 100K
R3            : 22K
R5            : 1K
R7            : 100R

Capacitors:
C1            : 10uF/25V
C2            : 22n
C3            : 10n
C4            : 3n3
C5            : 2p7
C6            : 22p 
C7            : 100uF/16V
Trimmer       : 0-30pF tuning capacitor

Mic           : ECM-60P

Transistors:
Q1            : BC338
Q2            : BC548B

The battery supply rails have been well tied together with respect to radio frequencies (C1, C2 and C7.) The tracks are also thicker. This makes the circuit a single “solid” block eliminating RF currents in different parts of the circuit. This also means the battery no longer has RF on it which makes the whole unit a lot more frequency stable. A battery is perfect choice.

Download the complete explanation of this FM Transmitter (include circuit diagram, component list, the circuit’s work) in PDF format:
[wpdm_file id=42]

Source: kitrus.com

circuit diagram

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View Comments

Lloyd Val says:

April 12, 2012 at 8:16 pm

Pls I need a diagram of fm transmitter with the highest frequency rate also a diagram of radio reciever,all with components.I will be greatful if my request is granted.Thanks
Kale says:

October 22, 2011 at 4:21 am

I want to make Fm transmitter and receiver could you help me to send circuit diagram and other related documents
regards
Ratheesh says:

August 5, 2011 at 12:03 am

I want a fm reciever circuit in 2kilometer capacity
Ashish Danai says:

July 18, 2011 at 10:00 pm

I am reading Diploma in Engineering. I Want to make a FM radio station for 95MHz Please send me the circuit diagram and components in detail.
supun says:

April 25, 2011 at 2:39 am

i am student. piease...., send me a 500M radio transmiter circuit diagram. if u help me i will be thankfull...
abraham says:

March 31, 2011 at 3:41 am

thanks the infomation is good, am a electronic student that have special intress in transmitter building and repair, back in africa i dont have tuitural or books to help me through, once again thank you and looking forward to hear from you
Partha says:

January 30, 2011 at 1:44 am

I am a electronics students.. plz send me a 1km range radio transmitter.. or how can I spend my transmitting range??in above circuit..if possible
Akin RA says:

September 18, 2010 at 5:34 pm

Please, I have gone through the FM Transmiter circuit diagram on your web site; but I have difficulty converting the capacitor values (nano/pico farad) to the numeric value such as 102, 103, 104, and so on which is common to the ceramic type. For me to purchase these capacitors (correct values), I must know these values. Please, kindly help me. Thanks.
RAHUL says:

July 24, 2010 at 3:00 am

iam student in a collegepleas sent me a circuit diogram of fm transmitter of 500m range.
gideon says:

December 21, 2009 at 2:06 am

i am pleased with your articles i am a student in a college please sent me a circuit daigram of fm transmitter of 2km range.