Proceed to Secure Checkout
MFJ ANTENNA-TALK #7
1/2 Wavelength "L" Antenna
The ½ wave Inverted "L" antenna, with Hi-Z feed point requires only a minimum ground to be an effective radiator. Accommodate coax lines with an L-Network match.
Use the formula: 492/fMHz (259.4 @ 1.9MHz for example) to find the overall length of the aerial, which is composed of H (Horizontal) + V (Vertical) components. Try to get the vertical section as tall as possible, since the current distribution is maximum at the midpoint of the aerial (129.7 Ft @ 1.9 MHz). That being true, it can provide good radiation from both H and V components. The H component can slope down (or up), but this tends to skew the max radiation towards the direction of slope, which is sometimes desirable. For instance: working VK/ZL, JA, Africa, or Europe.
The overall best advantage of the aerial is that only a minimum ground is needed unlike the 1/4 wave version. Make for 160, 80, 40, or 20 meters with the appropriate single-band L-network. Patterns vary per band if actually cut for 160, then used also on 40 or 80. 40 is good off the ends; 80 is good broadsides and vertical at the same time (more so than on 160). Use a tunable L-Network or any antenna tuner capable of matching high impedance loads, and it's a good multiband system. Discrete parts (wire, insulators, pre-cut coils, and capacitors) are available from MFJ.
All information, images, and documents on this website are the sole property of MFJ Enterprises, Inc. Any reuse or redistribution of the contents of this website are strictly forbidden without authorization from MFJ Enterprises, Inc.