The extensive demands to make a huge groundplane for your ELT antenna is based more on the lawyers' input than the engineers. The company insists that you put in this huge groundplane, which won't fit in 98% of the planes. Then, if you have to use your ELT and it doesn't work properly, they can say it is not their fault because you did not install it properly.
Run a piece of RG-58 FOAM coax to about 18 inches behind the cockpit area. Leave an additional 21 inches of length. Cut the cover and remove it without damaging the shield. Push the shield up so it becomes loose and work the center wire through the shield where the cover begins. Flatten the shield out and pull it to maximum length. Cut the shield off 22 inches long. Bend the center wire away from the shield about 90 degrees. Put the center of this new dipole antenna about half way up the side wall of the fuselage. Run the center conductor vertical and flox it into place. It will curve towards the center of the aircraft on the inside of the turtledeck. Run the shield down the sidewall and across the floor of the fuselage, and bond it into place. The antenna will check real close to a 1:1 standing wave ratio. Then you can concentrate on the really fun things, like sanding. Jim Vance va...@claflinwildcats.com
