I am building a 400 MHz transmitter and receiver for a hobby project.Can anyone direct me to a website or give a soln for the transmitter

 

It's not really a hobby project, UHF construction is extremely critical, which is why you're not likely to find many designs. You also have licencing problems, it's a fairly serious offence in most countries to use an unlicenced transmitter.

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PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

Here are a couple of websites that may help:
www.linxtechnologies.com and www.ABACOM-TECH.com

These modules are generally on frequencies that do not require an license for operation and as a result have limited range.

Having built many rf transmitters I agree with Nigel.
One of the problems with free running oscillators at UHF frequencies is the stability of the oscillation frequency. On method is crystal control at a lower frequency and then multplying the frequency a number of times to reach the UHF frequency. Another method is to SAW resonators, which I think the modules provided by the above websites may very well use.

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The great thing about electronics is unlimited ways to do the job. The only limit is one\'s imagination. I generally think my way is best.
Show me a different way. I have an open mind.

 

try to this site for serch 400MHz transiver http://www.chipcon.com.