The Yuma Hamfest will feature an antenna clinic on Saturday at 1:00 p.m. in the 4-H Building for those interested in building a tape measure antenna and attenuator suitable for locating hidden transmitters. Following the clinic, at 3:00 p.m., there will be a transmitter hunt (fox hunt or t-hunt) conducted on the grounds of the hamfest. You are welcome to join with your own equipment even if you do not attend the antenna clinic. In either case, you will need to provide your own 2-meter handheld.
The antenna clinic will be held in the 4H Building, and is an opportunity for people to build a 2-meter "tape measure" beam from a prepared kit. This antenna is primarily used for transmitter hunting, though other uses include finding stuck transmitters, QRM sources and jammers. People can bring their own parts if they like, or kits will be available for purchase. If participants choose, they can buy:
WB2HOL Tape Measure Beam kit - $18.00
K0OV Offset Attenuator (assembled & tested) - $27.00
Complete kit (antenna kit & and attenuator in antenna-mounted enclosure) - $60.00
There are limited quantities of antenna kits available and you should contact Marvin Johnston, KE6HTS to reserve a kit. Please indicate whether you prefer a 2Mhz or 4MHz offset attenuator. The 2 MHz is normally used with HTs that can't tune out of the ham band while the 4 MHz is used for everything else.
The offset attenuator is already assembled and tested and can be used with a 2 MHz or 4 MHz offset. The complete kit includes the tape measure beam kit and the attenuator mounted in an enclosure which becomes part of the beam of the antenna. The output connector is BNC, so anyone with an HT with an SMA connector needs to supply an SMA-to-BNC adapter.
Depending on experience, the build time for the antenna kits will range from 10 minutes to an hour.
Following the antenna clinic, people can test out their antennas and get some practice by attempting to find three "beginner" transmitters on 144.525 MHz located within about 50 yards of where the antennas are assembled.
The transmitter hunt will begin at 3:00 p.m. Five hidden transmitters will be placed on the fairgrounds and it will likely take inexperienced hunters about 1 to 1½ hours to find all five transmitters. Experienced hunters will be able to do it in about 30-45 minutes. The total distance for the hunt will probably be about a mile.
The antenna clinic and transmitter hunt is organized by an internationally-recognized expert in this part of the hobby, Marvin Johnston (KE6HTS). Marvin has been active in transmitter hunting for many years. Course setters for this years t-hunt are Joe Corones, N6SZO, and Joe Loughlin, KE6PHB, both well known for their t-hunting activities.
We are also planning a T-hunt dinner for Friday evening at a local restaurant (as we usually do). If you would like to attend, please contact Marvin Johnston, KE6HTS to confirm.
Marvin started International ARDF as a member of the first US ARDF team competing at the 1998 World ARDF Championships in Hungary. He has also competed in t-hunts in both China (2000) and Slovakia (2002.) Since then he has been an international jury member for t-hunts in the Czech Republic (2004), Bulgaria (2006), Croatia (2010), Serbia (2012) and Kazakhstan (2014.) Additionally, Marvin has coordinated the 2004 (So. California), 2007 (Lake Tahoe, California), 2012 (So. California), and 2015 (Colorado) US ARDF Championships.