I really need your help with this my fm transmitter circuit project !!

[Mg Myo Ko]

Hey, my friends,

I 've sucessfully constructed a FM transmitter.But its transmitting distance
doesn't meet with my satisfaction. For this reason , I'm going to turn to
another FM transmitter circuit project. The circuitry to be constructed is
in the attachment.

As I'm not a radio technician , there're many obstacles for me to overcome in
constructing that circuit.So , please help me , my friends , with this construction!
I ask for your help with my heart & soul.

Technical specifications of the circuit in the attachment are -

Working voltage ………………….. 12 to 18 v (DC)
Maximum current ……………….. 450 mA
Output power ………………………. 4 W
Frequency range ………………….. 88-108 MHz

In the parts list of that circuit ,

TR1 and TR2 are of type 2N2219 (npn) , and TR3 is of 2N3553 (npn) type.Wow!!
These types of transistor , I think , are very scarce or rare!! I couldn't buy these
models anywhere in my nation , Myanmar. This is one of two of major problems
I encounter!

So , I have to replace them with another transistor types. Therefore , what would
be the suitable substitutions for them? Be sure ,my friends , transistor types you
suggest are currently in use. I mean they must be available.

The next "big problem" that comes to me is that this circuitry uses RFC ( VK200 RFC tsok ).To say frankly ,my friends , I only know that RFC stands for "radio frequency choke" and I've never seen such a component!! How bad I am!? So where can I get these coils (RFC)? And could these "chokes" (RFC) be found in old circuits? Please, kindly give your helpful hands to me , my friends.Hey. dears! there is no "online store" available in my country!! So, I could not reach up to any "online stores." ( I mean "buying in online stores" is not available in my country , Myanmar.)

Dear my friends ,

I sincerely write the following lines with the words from my heart in a glimmering hope of " if someone of you reads these lines and be eager to help me."

The electronic components I list below (and also in the attachment) are not available in my country. But I desperately need them for my transmitter project.(Please , do not say ,my friends ,not to construct this project.One's hobby makes one crazy!!) Althrough I could be able to afford to buy them if they were available in my country, but they , indeed , aren't!!

Therefore , I would like to ask for help to someone of you who feels compassion on my writings. Dear, my friends , would you mind sending me a packing of these components listed below as soon as possible?

I really know that "Money is difficult to get." But I'm certainly sure I'm going to pay back the money to you who would send the packing to me , one day in the near future , say , when I have access to the online banking system.I think this is not too long to wait.


The address to which you have to send "the packing" is written in the attachment . You , my friend , just "print" that attachment and stamp it onto the packing addressed to me.( The lower part is written in my native language (Burmese) in order to make "sending the packing in my country " easy and sure there isn't liable to something bad. The address is fully completed.

( The List of components I desperately require are as follow

RFC (VK200 RFC tsok) = 5 or little more
2N2219 (npn) (Transistor)= 2
2N3553 (npn) (Transistor)= 2
LY89 (Phillips) (Transistor)= 1


Oh , my thread is a little long!! So , this is my sole and seeming , the last hope and only way to accomplish my transmitter project , really.

Thanks and waiting your replies,

 

[audioguru]

The circuit you found is extremely old so it uses obsolete parts. It is a project at Electronics-Lab online 4 Watt FM Transmitter and is also a kit from Smartkit in Greece.
Smartkit sells their kits all over the world.
It has enough power to be received on a cheap poor sensitivity FM radio but its high power will cause interference to many communications.
Its frequency is not stable and wanders all over the place and it will sound muffled when heard on an FM radio. It is designed for an obsolete "crystal" microphone but might work with a dynamic (coil and magnet) mic.


You can make your own coils with the instructions of the project at electronics-Lab. A pcb design and parts layout are shown.

 

[Mg Myo Ko]

Thanks .
Is there something better circuit like this one Please don't forget ,my friend , output must be 4 watts or more!

 

[audioguru]

In many parts of the world there are many FM radio stations. Governments do not allow a home-made transmitter to cause interference to an FM radio station so the output power is allowed to be only very low.

You can make the old and very poor quality FM transmitter circuit is you want.
Or you can make a modern FM stereo transmitter that works very well. Rhom makes a few FM stereo transmitter ICs that use a crystal-controlled frequency synthesizer with phase-locked-loop. Most of the MP3 to car radio FM tranmitter products use one of these ICs.

Silicon Chip magazine published a project called "The Micromitter" and a kit is available. You can illegally amplify its output with an RF amplifier.
Its schematic is here: