Progress has been frustratingly slow the last few weeks. Several trips on the road, for several days each, plus a bunch of things that needed doing around the house, all conspired to keep me out of the garage. The last couple of days I finally got back at the project, by having another go at the ELT antenna mount.

ELT antennae are supposed to be mounted on the top of the fuselage, as far aft as possible. The vast majority of aircraft have the ELT antennae sticking up from the rear fuselage somewhere. This won't work on the RV-8, as the canopy slides aft along the top of the rear fuselage. Some builders mount the antenna horizontally underneath the empennage fairing, directly below the vertical stabilizer, and between the root ends of the horizontal stabilizers. I didn't like that location, as the antennae pattern would probably be quite poor.

Many other builders put the antenna on the right rear arm rest, back beside the passengers right elbow, with the antenna running up the bulkhead at the passenger seat back. I had originally planned to use this location, but was troubled by the fact that the would very close to that bulkhead, which would also greatly compromise its radiation pattern.

I spent quite a bit of time pondering things, studying the aircraft. I considered mounting it ahead of the windscreen, on the forward fuselage, but I didn't fancy staring at it all the time I was flying. I eventually hit open a possible mounting spot in the cockpit between the two seats, near the canopy rail. I saw one RV-8 at Oshkosh with the antenna mounted in this location, so that firmed up this as a possible location.


I fabricated a bracket on Sunday, and clamped it in place to see how it would work. I originally had it further aft, and leaning a bit aft, to keep it away from the pilot's right elbow. But, that put the antenna tip right in the passenger's face as he climbed into the aircraft. I had to move it forward, and stand it more upright, to keep the tip a safe distance from the passenger's head.

Yesterday I painted the mount, and today I drilled the holes for the mount, and the coax cable that goes to the ELT transmitter.


The top of the bracket is angled to lean the antenna a bit inboard, to ensure that it is not hit by the canopy frame as the canopy is opened and closed.