Next Fox Hunt Sept 10 at 9:30AM
Come Out & Join Fox Hunt Saturday Sept 10 at 9:30AM
We haven’t had a Fox Hunt in several months. So, get your gear ready and plan your strategy to win this Fox Hunt on Sept 10!
In a fox hunt we search for a hidden transmitter using 2 meter hand held radios and directional antennas (typically a small yagi). The transmitter is typically hidden in a park, typically on the west side of Longmont.
It sounds simple, but use the next couple weeks to build or check your antenna and refine your strategy. Its more fun if you team up with another operator, or better yet, a friend interested in learning about ham radio.
The hunt usually breaks into 2 parts. Part 1 is getting close. Part 2 is the last 100 yards.
In part 1, you typically drive in the direction indicated by the strongest signal when you turn your yagi antenna. But, be aware that most small yagis have poor front to back ratio – so you may be mislead 180 degrees in the wrong direction. Front to side ratio is better, so you are less likely to be sent 90 degrees in the wrong direction. If you work with a 2nd team that starts at the opposite end of the search area, you can triangulate and get close, quicker.
Toward the end or part 1, the signal is so strong that you can drive in any direction and still have a very strong signal. That is the time to switch to a very poor antenna (or no antenna) and drive in different directions, noting what direction gets the strongest signal.
You would think Part 2 would be quick and fast. But, it can be slow and frustrating. Even with no antenna, the signal is so strong that you can’t sense a direction to walk. I thought an attenuator would solve this. But, unless you have a very well shielded attenuator, it acts like an antenna and makes the problem worse. The best strategy I know is to shift the frequency on your radio up or down 5 or 10 KHz. By doing that, you will get a much weaker signal and have a better chance of walking in the right direction.
Another close-in technique is to use a harmonic of the fox’s frequency. Say the fox is at 146.400 MHz. The third harmonic is 146.400 MHz * 3 = 439.2 MHz, which is in the amateur 70 cm band. If your HT is capable of receiving that band, then setting your VFO to 439.2 MHz should give you an attenuated signal.
You might choose to join the 8AM breakfast at the Hidden Café and then move directly to the hunt.
Hope to see you Sept 10!
Ed
WA7EM
