During our monthly meeting two members, Bill KR4LO and Randy K4WRD, gave the group a presentation on the fox hunt transmitter and direction-finding antenna they’d built in anticipation of the upcoming club fox hunt.
Bill had built the transmitting device to hook to his HT that will transmit beeps and his call sign at the end of one minute then pause for one minute and repeat.
Randy had built a representative beam antenna to hunt the above fox. He used PVC plumbing components in the main with various other parts like hose clamps and screws. He also added an attenuator to the rig to reduce the incoming signal strength as you, the hound, closed in on the fox so that the signal strength stayed on scale. Randy says the instructions used for building his antenna can be found at http://theleggios.net/wb2hol/projects/rdf/tape_bm.htm Information on building an attenuator can be found at: http://www.homingin.com/joek0ov/offatten.html And some ideas on foxhunting and radio orienteering at: http://www.homingin.com/equipment.html
Randy will solicit dates that the interested members suggest to meet at Bill’s place to construct our own tape measure antennas. Then we’ll set the date to have the hunt followed by a club-sponsored meal to celebrate the successful hunt.
Randy K4WRD presents on his tape measure beam antenna to the club at our march 2015 meeting.
Side view of Randy’s tape measure antenna during the meeting.
Alternate view of the antenna showing a package of some of the components and a cheap alternative for attenuating the signal on your HT by covering a cardboard tube with aluminum foil and then using it to slide over the HT’s antenna to reduce incoming signal strength.