SlimJIM and Antenna Gainflation

E-plane gain plots of J antenna variations

Understanding why SlimJIM antenna aficionados hype the gain in their marketing and discussions.

Ground effect

40m monopole over various ground conditions

Ground conductivity, permittivity and the effects on vertical monopoles.

Radials and their far field effects

H-plane gain of monopole with 1, 2 and 3 radials

Radials are peculiar things worthy of some explanation.

Slim Jim vs. Traditional J-pole Antenna

Measured gain of SlimJIM and J-Pole

Real measurements of a Slim Jim antenna and traditional j-pole antenna reveal the truth about their respective gain and pattern.

NVIS Gain of Loop and Dipole vs. Height

Observations from the Virginia QSO Party confirm simulation results concerning horizontal antennas and NVIS propagation.

Have your J-Pole and ground it too

1.06 GHz Test J-Pole Antenna

Tame the predictable mast currents found in any j-pole antenna grounding conductive mast using a simple stub. Shown is empirical evidence why this is a problem and a very simple solution all future grounded j-pole antennas should incorporate.

HF AHVD on 6m – Practical?

Tall 6m AHVD making local contacts.

Will the KX4O version of the 20-10m Asymmetrical Hatted Vertical Dipole work on 6m? Yes, sort of.

Build this Vertical Portable HF Antenna

Build this Vertical Portable HF Antenna

The Asymmetrical Hatted Vertical Dipole (AHVD) prototype is an easy to build, portable alternative to other freestanding vertical HF antennas such as the Buddipole.

Asy Hat Vertical Dipole

Three views showing a how a planed vertical need not always be the classic 1/4 wave monopole.

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.

40m Mastless NVIS Antenna

40m Mastless NVIS Antenna

Yet another 40m Cloud Burner design featuring a folded dipole driven element plus one reflector wire to facilitate 40m NVIS contacts without need of a tall mast. The design uses electric fence posts for support and needs no balun.