You can look at the two circuits posted here: http://www.techlib.com/electronics/lightning.html
I've built several of the original circuit for friends and they all work quite well. Parts values are not critical. I even built one that triggers a voice storage and playback chip that gives a verbal warning when lightning is detected.
can i ask u a favour?? do you have any articel about lightning that emit electromagnetic radiation that is similar to AM wave.. if u don't where can i get it.. i really need it..
Hello Fauziah;
I'm not really sure what exactly you are looking for and I am certainly no expert on lightning
There is an article available at **broken link removed** - Characterization of Lightning Electromagnetic Fields and Their Modeling. The best suggestion I can give you is to do a Google Search for "lightning electromagnetic waves frequency". This will give you over 80,000 choices and perhaps you can find what you are looking for.