This project started back in December of 1999. Mike (KB9VNB) and myself Jim (W9XL) participated in a local fox hunt. This was our very first hunt, and being rookies we came in dead last. We didn't even know how to use the body block method with a hand held transceiver at that time. This inspired the building of the (FOX BUSTER 1) unit. With a big thanks to Bob (K9VCN) for the circuits we needed. I am a Bio-Medical Engineer, Bob is an Electronics Engineer, and Mike is a Software Support Specialist.
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This information (pertaining to the Fox Buster 1) is free for Amateur use. Feel free to down load the schematic and pictures. We want to share this project with other amateurs who would like to build a Home-Brew RDF unit that works. There is Not a CPU to program for the (FOX BUSTER 1). Most parts can be purchased locally. A Radio Shack project box was used for the RDF unit. K9VCN can supply parts like the instrument amplifier Etc. You can contact Bob (K9VCN) via E-mail at the address just below here.
The (Fox Buster 1) is not to difficult to hard wire. It is of simpler design. There are no thoughts for having a PCB made for this unit. The displays physical lay out (21 LEDS) seemed to be the most challenging part of this project.
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Lets start with the Dual Antenna System. The aluminum box is 15" x 15" x 1.5". 1.5" C channels were used for the four sides. SO-239 connectors for the antenna mounts. Antenna materials are brazing rods. Shielded cable with drain for the antenna switching. Antenna spacing is 13.5". Front and Back are one pair and Left Right are the second pair of antennas.
The bottom photo view will show you the physical lay out of the dual antenna system. The important thing is to make the 174 coax lines from the antenna switching PCB to the SO-239 connectors the same (exact) length.
Check to make sure the diode polarity is correct. There are 4 diodes per pair of antennas. 1 on each SO-239 connector. Keep the length of the diode leads the same. To the right is a photo of the resistor and diode connection detail we used. RG-58 was used for transceiver feed line to antenna switching PCB.