I connected via a coax balun as found on "aeroelectric.com", secured to the rudder spar. Downside of antenna in rudder is coax has to flex when rudder moves.

Aerials made from radio shack cb antenna silver brazed into drilled 1/4 stainless bolts. Total aerial length = 25" with 1" pigtails from balun. Total =26" or 1/4…

The plans have no information to guide the installation of the optional fiberglass doors.

The builder resources on Zenith's website have an aged photo assembly guide that leaves out a key piece of info...The upper door sills must be trimmed 20 mm ( from 80 to 60mm in height). Otherwise the door hinges will not align with the door's upper flange, instead they will want to align on the plexiglass.

I confirmed my findings with another builder's experience here:…