Archive for the 'Antennas' Category

J antenna and variations thereof

J antenna an variations thereof

There are many ways to morph the basic J antenna into useful forms.

J Antenna Design Patent Grant

USD798847S1 showcases one more incremental step towards a J antenna that works with masts and feedlines.

Mast Mountable Antenna Patent Application

Front view of Mast Mountable Antenna

The “mast mountable antenna” patent application is now available to review and critique.

N9TAX 2m Slim Jim Antenna Review

Erroneous specs aside, the N9TAX VHF SlimJim antenna is an exemplary dipole.

The limits of aluminum antenna tubing

Aluminum comes in varying grades and the Diamond Antenna CP22E demonstrates why not all aluminum is created equal.

Runt radials

Antennas shipping with ineffective antenna decoupling are on the rise as manufacturers daringly advocate 1/12 wave radials work.

Diamond CP22E Antenna Review

Despite some antenna gain hype, the Diamond Antenna CP22E 2m base station antenna is a remarkable design achieving 5 dBi directivity in a slim low-profile design.

Decibel hell & the reign of antenna gain pain

A short history of antenna gain terminology and some guidance to muddle your way through some of the nefarious alternative facts you may encounter.

Displacement Currents

Kirchhoff's current law as boundaries.

Displacement current explains why the ends of dipole antennas have something more than zero current.

Of fields and feedpoints

Understanding how feed position along the half-wave dipole antenna affects the electric and magnetic fields around it.