Hi,
First of all, I have to say, "HOORAY~"
It is working!!!! Nothing is wrong with the circuit or the connection, tuning makes it to be complicated.
The DC voltage at the mic is 2.7 volts and the DC voltage at the collector of the 1st transistor is 2.8 volts.
I found that it is very very very very very difficult to tune the trimmer cap.
I used FM radio of my MP3 player and Fm radio of my friend's mobile phone, at 96.4MHz, it sounds very very poor at around 10 feet. Even when the transmitter and receivers are in side by side, the sound quality is still poor and much noisy.
It's really hard to tune the trimmer cap. I think maybe 0.1 degree can affect the transmission. Besides, I've bought a long screw driver which is said that used to tune a trimmer cap, but the front part is made from a small piece of metal (I think it is metal). When I used it for tuning, I can hear someting when the screw driver is touching the trimmer cap, when it is removed, the sound is different. Now I'm using my student card to tune, better and reliable
Now I'm having problem with the sound quality..
.. Anyway, thanks audioguru for willing to help..
Thanks