The transponder and VHF antenna are installed under the belly. The transponder antenna will be near the left fuel vent exhaust. This is inside the fuselage, behind the left rudder pedals with a small circular doubler.



This is the antenna outside.



The VHF antenna is under the right seat in the outer bay.



This si the doubler that will be riveted to the rib and to the fuselage skin.
I still have to deburr all the holes, countersink the doublers and dimple the skin.