At 9:00am on a hot summer Saturday, June 30, 2018, members of SCICSG and other area hams, gathered for some outdoor amateur radio fun in and about the shady wooded paths on the north end of Mill Race Park in Columbus, Indiana.
The “hunters” were chasing a “fox”, a small, self-contained, low power battery-powered radio beacon. The beacon and battery were inside of a re-purposed military surplus ammo can, that was hidden somewhere in the area. Operators used their hand-held radios to detect the automated signal put out by the fox beacon.
To perform direction-finding, operators used the RF shielding properties of their own bodies. By holding their HT radios to their torsos and turning slowly, they eventually found a direction where their body blocked the fox signal. At that point, they knew that the direction of the fox was probably directly to their rear, giving them an azimuth to turn around and walk towards. By repeating this procedure and continuing to verify the direction and strengthening signal of the fox, the operators would be guided towards the fox until they were practically on top of it. Once found, the remaining operators were called to gather around, and notes were compared as to what worked and what didn’t. Then, a fresh team hid it again, and the process was repeated.
In addition to gaining practical real-world experience with this useful technique, operators also learned how easily signals could be reflected off of water and masonry structures, giving false readings.
Thanks to Ken Rogoski K9KER for leading the fox hunt and for the use of his fox beacon, and to all those who helped organize the event. And, thanks to all the operators who participated.