Put a Foxhunting Beam on Your Vehicle
“What’s the best equipment for winning 2-meter mobile foxhunts?” That’s a question that I am frequently asked by hams contemplating their first search for a hidden transmitter. As you might expect, there is no simple answer. I have seen the radio direction finding (RDF) setups of hundreds of hams and each one is somewhat different, just like snowflakes.
To narrow the field of equipment choices, let’s presume that you are preparing for a beginners’ mobile T-hunt. You might have to drive 10 miles or more, so you need an RDF antenna that mounts on your vehicle. That way, you can find the signal direction while moving. You don’t want to be constantly stopping and getting out to take bearings. These requirements eliminate from consideration the “body shielding” technique and simple left-right buzz-box attachments for your handheld.
Weak, Bouncing Signals
The hilly terrain and large boundaries of southern California hunts make a high-gain antenna system a necessity. Starting points are generally on hilltops and often the hider will be dozens of miles away, running a couple of watts from a canyon, a riverbed, or maybe even a sewer. It’s important to keep hearing the signal after driving off the hilltop if at all possible. There is nothing more frustrating than having to continue in the direction from which the signal was last heard, hoping to catch some signal again soon. After all, the idea is to hunt down the signal, not to hunt for the signal.
For that reason, the favorite mobile RDF antennas for the bands from 144 to 450 MHz
