The design point: End effect is the capacitive and field behavior near an antenna’s open ends that makes a resonant wire physically shorter than a simple free-space half-wavelength calculation.
Why the complete system matters
Wire diameter, insulation velocity factor, height, nearby objects, end supports, bends, and feed arrangement change the shortening, so published formulas provide only a starting cut.
The assumption that breaks it
Applying one fixed “95 percent” factor to every insulated portable wire and geometry invites repeated trimming errors.
Build or deploy it correctly
Cut slightly long using a formula appropriate to the wire, install at final height and shape, measure, trim symmetrically in small steps, and record the finished physical and electrical conditions.
Configuration boundary
Use the exact product guide, electrical topology, geometry, materials, loading, feed, return path, support, and environment. Mechanical fit or a visually similar arrangement does not establish electrical equivalence.
