EFHW-xfrms

These are ~49:1, 75:1, or 81: ratio (~2500, 3750, or 4050:50 Ohms) UNUN transformers for EFHW antennas, just pick one and add half-wave long wire for the frequency of interest. Note that it will also work on its harmonics for example 3.55 MHz x 2,3,4…