Homemade Endfed Antenna (with matching transformer)

Some photos of a homebrew endfed antenna installation are shown below. The antenna is roughly 125 feet in lenght and operates from 80m to 10m with the aid of an antenna tuner.

Mounted matchbox with endfed antenna and counterpoise connected.
An RF choke installed near the feedpoint of the matchbox (snap-on ferrite core with several co-ax turns)

Antenna wire (~126ft) suspended in a spruce tree.

A plot of the resulting SWR across the HF bands is shown below (thanks to K8QS for lending an antenna analyzer):

The following plots show the SWR on 80m as the length of the antenna was trimmed in stage a several feet at a time. Moving left to right, one can see the antenna gradually getting better tuned for the 80meter band as the length in shortened.

Here are some photos I took of the different stages in the build of a matching transformer for an end fed antenna. The windings had 2 primary windings and 14 secondary windings yielding a 7:1 turns ratio, and hence a 49:1 impedance ratio (reflected from secondary to the primary side).


Magnet wire and 2 type 43 toroid cores

Core Winding: primary: 2 turns (bifilar);
secondary: 14 turns

Adding SO-239 connector and a cap

Final mathing transformer for
an end-fed antenna<