The article details the replacement of an obsolete Narco 50A transponder with a new Stratus ESG transponder and Stratus 2S, upgrading the aircraft's avionics.
The upgrade involved installing a more accurate 25-foot encoder and a new external GPS antenna, which now feeds satellite information to the Stratus 2S.
The installation process included careful removal of old equipment, mounting new components, and drilling/sealing a new hole in the fuselage for the GPS antenna, ensuring proper orientation and leak-free operation.