For those that enjoy the LNR of End fed antennas, but want to run more power, Balun Designs now offers an excellent alternative.
Built with the same craftsmanship as all our other units, this new model will allow you to either replace your current matching unit or construct a new higher power end fed half wave antenna.
We have also installed an additional stud which can be used for a separate counterpoise wire rather than forcing the use of the feedline’s coax shield.
Attaching a counterpoise wire to the common point of the auto-transformer provides the antenna radiator something to push against rather than the coax shield. The counterpoise wire does not have to be similar in length to the main radiator wire and just a short wire is all that is needed, about 0.05 λ. This calculates to ≈ 4.2 m or ≈14 ft for an 80m end-fed.
Caution: When used at full power rating of 1kW, the antenna must have a low SWR on the band selected and be used on a 50% duty cycle. Any SWR measurement taken with the transformer at the feedpoint should not exceed 1.5:1 with NO tuner in use. There are numerous configurations available online that will accomplish this on multiple bands (Google search “end fed half wave antennas”). If the transformer is used with an external tuner in conjunction with a single wire antenna typically 130-135 feet in length, power should be reduced on those bands that show an SWR above 1.6 to 2:5 without the tuner. A level of 500-600 watts is the maximum with a further reduction on any band measuring above 3:1.