Hi all.
I want to build 2 radio phones communicate with one another, when I speak from radio phone1 I hear my voice from radio phone2.
so I want circuit for FM Radio Transmitter and FM radio Receiver

so, the radio phone1 transmits the voice like "hi" and radio phone2 receive the same voice "hi"
Please help me

 

please help me

 

FM receivers are a lot harder than FM transmitters. My suggestion is to build a simple transmitter, then use a cheap commercial receiver.

 

What is your knowledge of electronics ?. Designing them yourself with little knowledge is going to be a very difficult task.

 

I love the invention so I want to build it by myself

 

Please I want explain parts this FM transmitter circuit

what's the mean C9 100pF

 

Read a book about electronics and then ask

 

The comment above is a bit harsh. But there is small truth in it however. The circuit you want described is actually quite complex, especially for someone with little or no understanding of electronics and it's unlikely that someone will take attempt to explain it since it will be many pages and alot of time spent trying to explain it fully. There are good books on this subject, most likely you are going to have to spend some time to acquire the knowledge needed.
If you still want to pursue these rf circuits i recommend you get your hands on a amateur rf communications book. There are plenty of good ones about.

 

Just a suggestion, look up any HAM (AKA, amateur radio) clubs in your area. These are exactly the kind of people you want to query, and they do what you're wanting to do now as a matter of course. We have a lot of HAMs on this site, I'm one. What part of the world are you? The odds are good you can find what you need locally, and receive instruction on the laws concerning these transmitters in your area so you can do it legally (always a plus).

 

Please I want explain parts this FM transmitter circuit

what's the mean C9 100pF

Q1 is the input amplifier for your voice. This feeds Q2, which is a mixer. The mixer combines the audio signal from Q1 with an rf signal created by Q2. The rf frequency is 1/(2*pi*sqrt(C*L1)) where C =C2//C3 and C3 is for tuning purposes. Note the oscillator in the collector of Q2 and its 360 degree feedback into Q2. C6 limits the feedback so that the oscillator has a gain of just above 1 volt per volt.