RADIO DIRECTION FINDING
1. T-HUNTS (Always Mobile, but may require a short hike at the end to find the transmitter)
T-Hunts have been around for as long as amateur radio has existed (over 100 years).
T-Hunts are exactly the same, except you are not told the exact coordinates, nor do you use a GPS. Instead, you are told a suggested starting location, the transmitter frequency, the search boundary, and the search time limit (how long the transmitter will be transmitting). Then you use your Radio Direction Finding Equipment and skills to triangulate the exact location of the hidden radio transmitter. When you find it, you sign the log book inside the T-Hunt Container, and if you are 1st, 2nd, or 3rd to find, you grab the medal or trophy inside the container as your award. After the time limit has ended the Hunt Master removes the transmitter, collects the T-Hunt Container and Log Book, and reports to MSRDF.com the ranking of the finders so they may obtain MSRDF member points toward future certificates and year end awards.
The Goal: The primary goal is the efficient use of radio direction finding skills, navigation skills, and direction finding equipment (radio, directional antenna, map, compass, GPS) to locate the transmitter. Some hunters like to form a team (single vehicle or multi-vehicle) to work together, much as they would when tracking down a source of harmful radio interference (QRN/QRM). Some hunters also like to compete with each other to be one of the first to find the transmitter, for them a higher ranking on the found list is their goal.
Day & Time: T-Hunts are usually held on Saturdays at various times.
Suggested Starting Location: The suggested starting location will be a parking area. The exact location depends upon the Hunt Boundary and will be announced by the Hunt Master in advanced.
Time Limit: Fox Hunts usually last between 4 and 12 hours, depending upon the size of the Hunt Boundary and the transmitter hiding location. Sometimes the longer time limits are given, not based on the Hunt Boundary, but instead to allow people to participate at a time which is convenient to their schedule. The Time Limit will be announced by the Hunt Master in advanced.
Search Distance: The potential distance hunters may end up covering during any given T-Hunt will depend greatly upon their RDF skills, but will be limited by the event's specific Hunt Boundary. These distances usually range from 3 miles for low power radios, to multi-counties for high power radios and/or large directional antennas.
Hunt Boundary: The Hunt Boundary will either be given as:
A. A distance in miles from the center point of a circle, with the center point being the starting location.
B. A boundary, such as the city limits of a town, or an entire county, or in some cases a geographical boundary, such as a national or state forest/park.
Multiple Transmitters: Occasionally a T-Hunt will have two or three transmitters placed in different locations, all hear-able from the Suggested Start location, either on different frequencies, or on the same frequency alternating transmissions every sixty seconds. The goal is to find as many of these transmitters as you can during the time limit. You can hunt for them in the order of your choosing.
Progressive T-Hunt: Occasionally a T-Hunt will have two or three transmitters placed in different locations, but only the First Transmitter can be heard from the Suggested Start location. Once you arrive at the First transmitter, you will be able to pick up the signal from the Second Transmitter, and so on, for up to three transmitters. Thus they must be found in progressive order. (We plan to host a four transmitter Progressive Dinner for our year end Christmas Party. Each course of the meal will be at a different location. The transmitters will be turned on and off in the following progression: Appetizers, Soup & Salad, Entree, and Desserts.)
Hunt Frequency: 146.565 simplex is our standard T-Hunt frequency. However, occasionally we may use a different frequency.
Transmitter Cycle: The transmitter cycle is how long the transmitter will alternate between transmitting and silence. This depends upon the transmitter power chosen and the power source (battery, solar panel, AC power supply).
Transmissions are usually for 45 to 60 seconds, followed by anywhere from 15 seconds to 4 minutes of silence. All transmitters must give their owner's callsign during the last part of every transmission.
A typical cycle for a small 15mW MicroFox transmitter might be:
If there are multiple transmitters hidden they will either:
A. Transmit on the same frequency and alternate their transmission time with each other.
B. Transmit of different frequencies (the frequencies will be sufficiently separated so as to not interfere with each other or their harmonics). In this case some of the transmitters may be transmitting at the same time.
The Morse Code transmission sent will be "MO" followed by dits. The dashes alert you to listen up. The dits indicate the transmitter number.
After the Dots, the hider's Callsign will ID in Morse Code. This will be followed by a specific period of silence, and then the cycle will repeat.
Transmitter Power: The power setting used will be determined by the type of transmitter used and the Hunt Boundary. The larger the boundary, the more power needed to be heard by the Hunters. In most cases, directional antennas (yagis, quads, or loops) will be needed to pick up the transmitter’s signal. The Hunt Master may, or may not, reveal the transmitter power in advanced, depending upon how challenging he wants to make the hunt.
Antenna Polarization: Possible Antennas Polarizations are Vertical, Horizontal, and more rarely Circular. The Hunt Master may, or may not, reveal the antenna polarization in advanced, depending upon how challenging he wants to make the hunt. Polarization greatly affects reflected signals. Therefore, learning how to determine a transmitter's antenna polarization is an important radio direction finding skill to develop.
Odometer Conversion Factor: You will NOT need an Odometer Conversion Factor for T-Hunts, because these are (with a few rare exceptions) come and go when it is convenient hunts, with folks starting at differing times. Since no one is at the start or end to check your mileage, awards are given based on the order in which hunters find the transmitter (sign the T-Hunt Log Book), not on the mileage they accrue. And the awards (trophies or medals) are in the T-Hunt Container for you to pick up if you are 1st, 2nd, or 3rd to find it. (Odometer Conversion Factors are only used for Mobile Fox Hunts)
T-Hunt Planning: Persons wishing to hide a transmitter for a MSRDF T-Hunt, must carefully plan the hunt in advanced and do a dry run test to determine the Hunt Boundary. of their transmitter in advanced. Then they must submit the following standard T-Hunt Plan information to to us via email (info@MSRDF.com) to have it posted it on our website.
Date: Saturday, February xx, 20xx
Suggested Start Location: (The transmitter signal, though faint, must be able to be picked up from this location with a directional antenna aimed in the direction of the transmitter): Give the exact GPS coordinates and a brief description N32 26.234 W 089 40.876, Parking spot on top of hill.
Hunt Boundary: Within 3 miles of Suggested Start Location
Hunt Time Limit: Start Time:10:00 am End Time: 2:00 pm
Transmitter Cycle: MOE
Award Classifications: Individual Hunters, Class One Mobile Team (Hider must provide 1st, 2nd, and 3rd place trophies or medals for each classification)
T-Hunt Hunter Classifications:
Mississippi Radio Direction Finding uses the following Classifications for award purposes and our member points system.
The Individual Hunter Classification is always included in each of our T-Hunts. Some of our events include one or more of the Team Classifications. In T-Hunts which include two or more classifications, participants must decide which classification they wish to participate as when they start.
1. Individual Hunter: This includes individuals hunting by themselves. This classification also includes families, couples, or friends, who want to participate together. These groupings may hunt as an Individual Hunter, as long as all of the members in their group stay together throughout the entire event, and all share only one RDF radio and antenna among them. When an Individual Hunter wins an award, he also receives MSRDF Member Points.
2. Pedestrian Team: There are no Pedestrian teams in T-Hunts, because all T-Hunts are mobile event.
3. Class One Mobile Team: Class One Mobile Teams consist of one vehicle. All Class One team members must ride in the same vehicle throughout the entire event. Usually, they each play a different role in the team: Driver, Navigator (Map Reader), Antenna Worker, etc. They may each have their own RDF radios and antennas, but do not have to. When a Class One Mobile Team wins an award, they all share the one team award. However, individual members of the team will receive MSRDF Member Points. If you don't want to share the victory, or an award, participate as an Individual Hunter
4. Class Two Mobile Team: Class Two Mobile Teams consist of two, or at most, three vehicles. Each of the vehicles can have as many persons in them as they will legally hold. Each vehicle must have its own RDF equipment. Multiple vehicles work together to triangulate the exact location of the Transmitter/s. (Class Two Team Triangulation: Each vehicle in a Class Two Team deploys to a different location to take bearings, shares their bearings with the group, the group draws all of the bearings onto a map, where the bearing lines cross is a very good indication of where the Transmitter is located.) Class Two Mobile Team members may also use radios to coordinate their hunt, as long as they use a frequency which is not close to that used by the Transmitter and do not give out GPS coordinates or bearings over the radio. In some areas, where teams have cell phone coverage they may send text messages to each other conveying coordinates and bearings. However, teams need to have a back up plan, because not all of the areas where we hold T-Hunts at will have good cell phone coverage. When a Class Two Mobile Team wins an award, they all share the one team award. However, individual members of the team will receive MSRDF Member Points. If you don't want to share the victory, or an award, participate as an Individual Hunter
NOTE: If a T-Hunt only includes the Individual Hunter Classification for award purposes, that just means that there are only three awards (trophies, medals) and they are only available to be grabbed by the first three Individual Hunters (in separate vehicles) or Mobile Teams who find the transmitter.
Just a few:
Do not let your competitive nature get in the way of anyone else enjoying the event. Its just a game, keep things light and enjoyable.
Individuals and Teams are not allowed to assists other Individuals and Teams.
The decisions of the Hunt Master and in lieu of him, the Transmitter hider are final.
No arguing or complaining. We are here to have fun.
Do not break the law, trespass, or drive over the speed limit.
Any participant who beaks, or attempt to circumvent, the written rules, instructions, conventions, and procedures given on MSRDF.com and/or given verbally by the Hunt Master and his representatives (The Transmitter Hider), will be disqualified from ranking, awards, and points in the event. In certain egregious cases individuals may be disqualified from participating in future events.
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