Adding 0.05 wavelength wire to EFHW antenna
I add a 0.05 wavelength wire to my previous end-fed vs. center-fed dipole tests and plot the results.
Ham Radio . Magnum Experimentum
Antennas, experiments, engineering and other articles of interest to radio folks.
I add a 0.05 wavelength wire to my previous end-fed vs. center-fed dipole tests and plot the results.
EIRP measurements of the 2m end-fed half-wave HT antenna from MFJ aids understanding a dipole is a dipole no matter where you feed it.
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.”
After three years of mobile operation, I review the Diamond Antenna NR770HBNMO with appropriate K515SNMO mount including pattern measurements.
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.
Mobile antennas have been around for decades, but assuming they perform the same is, sadly, a poor assumption as this comparison of Laird and Larsen VHF NMO EFHW aerials reveals.
Careful selection of quality probes joined with the Raspberry Pi offerings yields a wireless E and H field sensor for accurate antenna analysis.
The Raspberry Pi Zero brings nearly off the shelf gear to the task of generating an RF test signal from a completely wireless, small, self powered device about the size of a D cell.
Simulations suggest end-fed and center-fed half-wave dipoles share sensitivity to various feedline lengths, but in differing and manageable ways.
Does one really need to upgrade the antenna that came with your HT? Presented are EIRP measurements of various aftermarket HT aerials to help understand the trade space.
Understanding how feed position along the half-wave dipole antenna affects the electric and magnetic fields around it.