EFHW LNR Precision EF-10/20/40MKII Test Data
Basic tests of the LNR Precision EF-10/20/40 multi-band portable HF EFHW antenna including S11, SWR and a bandwidth check of the match box.
Ham Radio . Magnum Experimentum
Antennas, experiments, engineering and other articles of interest to radio folks.
Basic tests of the LNR Precision EF-10/20/40 multi-band portable HF EFHW antenna including S11, SWR and a bandwidth check of the match box.
The background and details of the LNR (Par Electronics) EF-10/20/40 end fed half-wave multi-band portable HF antenna. Come see what’s inside the mysterious “black box.”
Testing confirms an end-fed dipole can energize the radiator nearly as well as a center-fed without need of additional counterpoise or other extraneous conductors.
Simulations suggest end-fed and center-fed half-wave dipoles share sensitivity to various feedline lengths, but in differing and manageable ways.
I take a moment to document observed differences between end-fed antenna transformer topologies with and without ferrite core materials with a focus on the reactance compensation.
Understanding how feed position along the half-wave dipole antenna affects the electric and magnetic fields around it.
Operating QRP portable from the back of a Subaru during activation of the rare VQP city of Manassas Park (MPX).
KX4O/p Summits on the Air (SOTA) activation of Hawksbill Mountain (W4V/SH-001) on New Year’s Eve on 40, 20 and 10 meters.
We re-introduce the theory and origins of Cebik’s (W4RNL) Asymmetrical Hatted Vertical Dipole (AHVD) antenna with the hope to facilitate a vertical polarization portable 20-10m aerial for portable operations.