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.
![]() |
![]() 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< |