[amplifier]

Can anyone help me to find an amplifier THS4012?I couldn't get it anywhere.I want it desperately for my final year project.Where can i buy it?please help me.

[telephone billing machine]

I want to build a telephone billing machine.Can anyone give me a detailed circuit of telephone billing machine?The circuit should be capable of detecting and storing number of calls dialed and received and should be able to print out the bill.I want it very soon.So please help as soon as possible.

[TV transmitter(for educational purpose)]

I've got a video transmitting circuit toany TV set near it.I want to build it for my own sake.But I've heard that It is very difficult to build and the problems occurs in frequency tuning.Is it true?When i've got a ready made circuit,do i still need to doubt on its completion?Can any one suggest me 100% efficient video transmitter circuit so that i can build it blindly?