The composite antenna manufactured by Advanced Aircraft Electronics, Inc of Ellwood City, Pa has proven to be an excellent unit for installation inside the fuselage of the Stearman. In particular, this unit works really well with aircraft retaining the unshielded ignition systems. It is far enough away from the engine to provide noise free operation of the radio.
The antenna element is mounted in a flexible fiberglass base and has a conventional BNC connector for the lead to the radio. The Manufacturer recommends that the antenna be mounted as vertical as possible for the best reception. The Stearman will not let you put it quite vertical, but the slight angle does not seem to affect the antennas performance.
The installation of the antenna is pretty simple, though be it somewhat awkward on a covered airplane. Start by cutting a piece of 3/16 “ plywood 45” X 2”. Make sure the antenna and the plywood are dust free. Apply a bead of RTV the length of the antenna and center it on the plywood. A wallpaper roller helps push the antenna into the RTV. Cut two sticks to use with clamps to protect the antenna and clamp the antenna to the plywood. Let it sit for 24 hours. Remove the clamps at that point, trim the excess RTV and you are ready to mount the unit in the fuselage
This is where it gets tuff if you installing it in a covered fuselage. The antenna has to go to the rear of the baggage compartment bulkhead. It fastens to the cross tubes with Adel clamps and 10-32 machine screws. The lower tube is easy. The upper tube is at an angle and a bracket will have to be fabricated to mate with the clamp. Mount that to the plywood first. At this point the lead from the radio can be hooked up and the system tested.
Note: The manufactures installation manual has some good tips and detailed installation instructions and is the official source for that information.