The article details the replacement of a failing and obsolete Narco 50A transponder with a modern Stratus ESG system in an airplane.
The upgrade involved installing a new transponder rack, a more accurate encoder, and a new GPS antenna, which required drilling a hole in the fuselage and careful positioning.
New antenna cables were routed to connect the GPS antenna to the Stratus ESG transponder, which now provides satellite information to a connected Stratus 2S unit, no longer requiring a direct view of the sky.