direction finder receiver

could anybody give me a circuit of a simple radio direction finder receiver. or please tell me how to convert a standard fm reciever into rdf by using a homebrew antenna.

You need a receiver with a Field Strength meter.
For antenna you can use a simple directive Yagi (e.g. 2 elements ? driven and reflector, or for better performance you can add the 3rd element - director).
If your FM receiver do not have a ?Strength? meter, can try to pick up the signal before the limiting circuit, amplify and detect it.

For antenna you may check description of any fox hunting receiver in amateur literature. There are some very easy to build antennas. Probably the easiest is telescopic vertical (electrical part) with coaxial loop as a circle (magnetic part). You may make it for a half an hour or so.

BR,
RF-OM