Tuesday, September 27, 2011

Fox hunting bidirectional loop

this type of antenna is a Receive Only antenna.  when hunting RF signals you are triangulating RF signal strength. you do not need to transmit.   This antenna is a simple one to build and it can be fashioned out of any type of wire from a coat hanger to brazing rod or even aluminum rod or copper tubing.   I fashioned this one from aluminum rod left over from the LPDA project.

Using a tubing bender, or by hand bend the antenna conductor material in a complete 7 - 8" circle. Now  cut the circle into two equal halves.  Now take a piece of non conductive material, like CPVC TEE which I used and cut it in half and drill two holes. One hole in each side of the tee. flatten your antenna rod half and drill a similiar size hole in that. and fasten with #6 nut and screws. At the top of the loop slip a piece of shink tubing over both ends, but be sure to maintain a air gap of 1/2" between the ends of the loop.
 now you can connect a bnc or sma connector, whichever is needed to connect to your handheld.  Connect the short coax just like a dipole.  center to one side and shield to the other.
 It is that simple to build a bidirectional fox hunting antenna.