This article applies the improved model: An improved simple Simsmith model for exploration of a common EFHW transformer designs (v1.03) to the design at Another small efficient matching transformer for an EFHW – 2643251002 – #1 – design workup.
Above is the prototype transformer wound with 14t of 0.71mm ECW tapped at 2t. The mm rule gives some scale. The turns are close wound, touching on the inner diameter of the core.
Above is a screenshot of the model calibrated to measurement of the prototype.
Above is the measured InsertionVSWR (blue) and InsertionVSWR (magenta) and Loss chart from the model.
The model and its dependencies are attached.