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An End Fed Half Wave Antenna


As a rough guide, a capacitor of 50pf across a winding of say 30 turns is a starting point for 40m. Some experimenting with turns and tapping point is necessary. The coil former used was about 1/4 inches in diameter as found in old IF transformers
post 18 Apr 2024
An End Fed Half Wave Antenna

Antenna End Fed Links

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Antenna EFHW 20m/15m/10m
Attualmente utilizzo come antenna un semplice filo di 10 metri impiegando come contrappeso un filo di 5 metri buttato per terra

Antenna end fed per i 40 metri in soli 11 metri
L'alimentazione con cavo coassiale, da un solo lato è molto utile, per chi ha problemi di spazio

Antenna filare casuale
Antenne filari di lunghezza pari a 1/4 d'onda e oltre in riferimento alla frequenza della banda di trasmissione

Come ascoltare le HF con una filare piu' o meno casuale
Conviene quindi adattare l' impedenza con un piccolo adattatore in grado di coniugare antenne da 300 / 500 Ohm con l' ingresso a 50 Ohm

EFHW the end-fed half wave antenna
EFHW as an ideal temporary antenna for the hiker or camper. Ease of installation appeals especially to me because of my long life of sorrows trying to get lines through trees. I don't have a pitcher's arm and I've proven to be fairly inept with various slingshots and other antenna raising contrivances. Amazingly enough, just one good shot over a 20 foot limb can be all it takes to put up a quite functional 40 meter EFHW in an inverted vee configuration


Take off angle of horizontal antenna

Take off angle of horizontal antenna For horizontal polarization, the electric field will move sideways on a horizontal plane, while for vertical polarization it will oscillate up and down on a vertical plane

Rx antennas 4Square Rx Vertical Array

Rx antennas 4Square Rx Vertical Array My frequency design of 1.825 MHz a 90 degrees line would be 33,70 metersinstead of the previously calculated 33,27 m

Calculo da Antena Bazooka

Calculo da Antena Bazooka A double bazooka antenna is a combination that has a complete coaxial wave multiplied by its velocity factor and a total end-to-end length of 1/4 wave for each side affected by another driver shortening facto